Connecticut Preparedness

[hayes1966]

A friend sent this via email to me. I believe it was taken from another board but don't have the link.

HANDLOADING TIPS for 9mm
The following is a compilation of handloading tips for 9x19mm that have been contributed by CZF Members. I have given credit to individual members when they are directly quoted, but the majority of the text represents the general consensus of several dozen reloaders who also own CZs. I want to thank everyone who has contributed to the CZF Reloading Forum over the years. There is a wealth of knowledge here that has helped me, and I hope this "compilation" will be useful to new reloaders in particular.

Much of this information is generally applicable to all cartridges, but the 9x19mm (a.k.a. 9mm Luger, 9mm Parabellum, et al.) will be the only cartridge covered in this presentation.

The following is in no way intended to substitute for a reliable general reloading manual. I cannot begin to fully present all of the necessary information in this format. Without having read a general manual such as the Hornady, Lyman, or Speer offerings, much of this article will not even make sense, I'm afraid.

Contents

I. General Introduction

II. Cases

A. Brands
B. Sorting by Headstamp
C. Trimming Cases
D. Cleaning 9mm Cases
E. Lube with Carbide
F. Summary

III. Bullets

A. Bullet Materials
B. Bullet Shapes
C. Bullet Weights
D. Summary

IV. Powder

A. Introduction
B. Powder Density and Volume
C. Powder Burn Rates
D. Other Considerations
E. Some Thoughts on Powder Selection
F. Summary

V. Primers

A. Primer Types and Characteristics
B. Primer Brands
C. Primer Seating
D. Safety Concerns
E. Summary

VI. Tips and Techniques


A. Powder Safety and Selection
B. Die Selection
C. Press Selection
D. Bullet Selection and Seating
E. Overall Length
F. Crimping

VII. Parting Shots




I. General Introduction

9mm may be my favorite cartridge to reload. I mention this because 9mm has a bad reputation with some older reloaders. Thirty years ago, few people reloaded 9mm, and suitable components were difficult to obtain. Older Hornady manuals give load data using 158gr .357" diameter bullets! Most of the inexpensive brass was military surplus, which posed its own difficulties. Few people loaded for semi-autos in general in those days, so reloaders would frequently encounter problems with crimp, etc. 9mm came to be known as a "tricky" cartridge to reload.

By and large, this is no longer valid. The availability of quality components is at an all time high. A lot has changed in the last thirty years, and 9mm is now the most frequently reloaded handgun cartridge in the U.S. Dies, techniques, and powder selection have also improved during this same period.

9mm is a direct descendant of the first smokeless handgun cartridges, and it was never intended to be used with black or semi-smokeless powders. It is somewhat peculiar in that it is actually a 7.65x21mm (.30 Luger) cartridge cut down to accept a 9mm (.355") bullet. (The slight body taper of 9mm is a result of this conversion.) For these reasons, case volume is relatively small for a cartridge that peaks at 35,000 psi (SAAMI standard). 9mm is not forgiving of carelessness. A new reloader should not be concerned about loading 9mm as their first cartridge, but he or she should understand that it does have a smaller margin for error than some other common cartridges.



II. Cases

A. Brands of Cases

Once-fired 9mm cases are as common and as cheap as dirt. This can be a mixed blessing. Pitch any case that is in any way suspect. This is good advice in general; take it to an extreme with 9mm. It's too common to fool with a damaged case mouth, strange brand, etc.

The vast majority of brands of 9mm cases are suitable for reloading and very high in quality. They have to be, because many foreign manufacturers simply slap a commercial headstamp on their military cases. That said, don't even bother with a headstamp that you don't recognize as a major player. This is not for safety or quality reasons so much as consistency. You may never find another 50 "Dominion" 9mm cases ever again. When you are first starting out, small lots of cases like this are useful, but they aren't worth fooling with when loading in quantity.

CZF members prefer the following brands of cases, in no particular order:

1. Sellier & Bellot (headstamp "S&B");
2. Federal (headstamp "FEDERAL");
3. Winchester (headstamps "WINCHESTER," "W-W," "WCC," etc.);
4. Norma (headstamp "NORMA");
5. Israel Military Industries (headstamps "IMI," "TZ," and "UZI");
6. Starline (headstamp is two stars separated by a line);
7. Speer/CCI (headstamps "SPEER," "CCI");
8. Dynamit Nobel/GECO (headstamp "GECO");
9. Magtech (headstamps "CBC," "MAGTECH");
10. Hornady (headstamps "HORNADY," "FRONTIER");
11. PMP (headstamps "PMP," "DENEL").

The above brands of cases are not exactly equal in all respects, however. Speer/CCI cases are easier to load with CCI primers. Speer and Federal cases are not available as new component cases. Hornady is usually not worth the extra expense for new component cases. Starline is only available as new brass; IMI and Hornady might as well be, even though they do load factory ammunition. S&B has relatively tight primer pockets, particularly if you do not remove all of the lacquer. Norma cases are the most highly regarded, but they are now extremely rare in the U.S., as neither 9mm component cases nor factory ammo have been available for some time. On the bright side, most of the GECO 9mm uses cases manufactured by Norma. PMP commercial cases (blue boxes) are fine, but military PMP/Denel 9mm cases have Berdan primers.

CZF members generally consider the following brands to be less desirable for reloading purposes:

1. Remington (headstamps "R-P," "UMC," etc.);
2. Fiocchi (headstamp "FIOCCHI");
3. PMC (headstamp "PMC");

Remington brass is softer than the other major U.S. brands. Fiocchi has several idiosyncrasies, such as shorter than normal case length. Once-fired PMC brass can require chamfering. These are all good cases for reloading purposes, but not quite as desirable as the previous eleven.

Do not attempt to reload cases with the "A-Merc" "American," or "AAA" headstamps. They are substandard in every regard. No one at CZF has any direct experience with "Ultramax," but their cases are probably similar to A-Merc. Many people advise against reloading 9mm NATO brass. There is usually a primer crimp to remove, even if it is not Berdan primed. If it is brass from a high pressure submachine gun load, it may not be suitable for reloading.

The general consensus is that your own once-fired brass is the best source for 9mm cases. The best values from a reloader's standpoint are probably value packs of Winchester USA 115gr FMJ or case quantities (1,000 rounds) of S&B 115gr FMJ and GECO 124gr FMJ. S&B and GECO are less common. Depending on where you shoot, it may be difficult to avoid mixing up your cases when shooting Winchester headstamps. In my own opinion, GECO cases are the highest in quality, but they do not appear to significantly improve accuracy.

CZF members who buy significant amounts of new component cases appear to prefer Starline, Winchester, and IMI, in that order. There is some evidence that IMI makes many of the Winchester 9mm cases, but we cannot directly confirm this. IMI/TZ headstamp brass is less expensive than Starline or Winchester. I generally buy IMI cases because no one else at my range uses them.


B. Sorting by Headstamp

DO sort cases by headstamp. Whenever you switch headstamps, back your load off by as much as either 10% or at least 0.3gr of powder if you are anywhere near a max load. Work up the load all over again with the new case type. There are two reasons for this. First, the manuals aren't kidding when they say that different brands of cases vary in volume. It can be dramatic at times. Be especially careful when switching to Remington and Fiocchi cases; they are lower in volume than other brands by a noticeable amount. (Fiocchi cases are fine on their own, but they are so different from other brands that they will cause serious problems if the seating die is not set for them.) Second, accuracy will be significantly degraded when shooting mixed headstamps in the same magazine, even in a service pistol like the CZ 75.

NOTE: This is probably the one subject on which CZF members have a significant difference of opinion. Many 9mm shooters do not sort by headstamp, or at least not for light practice loads. Personally, I definitely recommend this, particularly for new reloaders. It seems like more CZF members sort by headstamp than do not, but I have not counted.

C. Trimming Cases

Virtually no one trims 9mm brass. The general consensus is that you lose the cases too often for them to flow to maximum length. Also, it's too easy to mix trimmed brass up with other range pickups. Accuracy does suffer from ignoring case length. I have never found it necessary to trim 9mm cases when segregating lots of my own once-fired brass. Theoretically, they should all be the same length if each case in that lot was loaded the same each time, the same number of times. In practice, they aren't of course, but this is preferable to ignoring case length all together.

ScottB offered this advice: "I trim all my cases. This is scoffed at by some, but not all brass is equal length, even new brass from the same bag. You should do it once before your first loading, and never bother again. No better way exists than Lee's cheap little setup and a variable speed drill. The Ball stud cutter makes it even better."

I will say this about trimming cases. Many people who obtain better results with the Lee Factory Crimp Die in this cartridge are probably just "canceling out" the case length variations. No one ever complains about the extra step of the FCD, yet few people will take the trouble to trim cases.

In my honest opinion, you can't get away with both ignoring headstamps and ignoring trimming. Safety will become an issue at some point by ignoring both, and your accuracy will become inferior to commercial ammunition. I understand that 9mm accuracy is a relative thing. Obviously, no one is hand-weighing primers for 9mm, but at some point you would be better off throwing rocks if you keep cutting corners! In summary, sorting by headstamp should be done for both safety and accuracy reasons. Trimming 9mm is necessary for best accuracy and ease of loading (see Tips and Techniques below), but it generally will not be necessary for safety reasons if case lots are segregated.


D. Cleaning 9mm Cases

I am not aware of any volume 9mm reloader who does not clean his/her cases. Notice, I did not say "tumble their cases," but I would guess that over 80.0% of these people are using a tumbler or vibratory cleaner of some sort.

Obviously, a tumbler costs about as much as an entire Lee Anniversary Kit, so some people will need to consider other options until they care to spend the money. Fortunately, you have several, but they are all fairly labor intensive. These can be summed up as "dry cleaning" and "wet cleaning."

The simplest dry cleaning technique is to wrap about @300 9mm cases in a bath towel. (Too many or too few do not work nearly as well.) Make a rattail and roll the towel around on the floor with medium hand pressure for about five minutes and inspect. If they look pretty clean, you can stop; if not, keep going. If you are patient, you can actually clean cases pretty effectively this way. Remember to shake the crud out of the towel each time you check the cases.

Richard Lee advocates using steel wool or Scotchbrite to clean cases by hand. I have no doubt that this works well, but I can't imagine a more labor-intensive method.

Wet cleaning techniques are more common. There are a number of products designed specifically for this purpose. In the long run, using the Lyman cleaning solution will cost nearly as much as a tumbler and its associated costs (media and additive). Fortunately, you don't need to use the Hornady and Lyman cleaning solutions. You can even use soap and water. You will find a number of suggestions for household products for wet cleaning on the internet. Never use products that contain any ammonia whatsoever. These will damage the cases.

Obviously, the cases get wet when using a wet cleaning method; this is a major drawback that cannot be fully appreciated until you try to deal with 2,000 wet 9mm cases. You have to have some space and patience with this method. Air drying works best. You should never try to speed dry cases with anything except a lamp or hairdryer. An oven cannot hold a low enough temperature. Cases get very hot upon firing, but they aren't designed to heat up to 175-200 degrees and stay there for a while.

Here is a tip that I picked up from "http://www.reloadbench.com." You can obtain excellent results by cleaning cases with diluted or straight cider vinegar. I find that just enough straight cider vinegar to cover the cases works best. Here's how: 1) Deprime cases in a decapping only die (see below). 2) Place cases in a bucket or similar plastic container (has to be plastic or glass). 3) Cover the cases in cider vinegar. It can be slightly diluted, but don't get carried away. The acidity of the vinegar does all the work. 4) Soak for 20 minutes, no longer. Some agitation of the cases helps. 5) Immediately drain away the vinegar. You can reuse the vinegar once or twice, but I don't think it is worth the trouble. Corrosion will begin to occur if you leave the cases in vinegar indefinitely. 6) Rinse the cases thoroughly with water. 7) Drain; a collander helps. 8 ) Air dry. This works as well or better than any of the products marketed to reloaders or any of the "mystery formulas" I have seen on the internet (most of which use vinegar anyway). You can buy everything you need for $6-7 at the Dollar General store.

After the cider vinegar method, concoctions of soap, water, white vinegar, and lemon juice appear to work best. Essentially, this just adds acidity to white vinegar, giving it the same characteristics as straight cider vinegar. I don't see much point, as the soap just seems to make the cases harder to rinse off.

In my opinion, you almost have to deprime cases before using a wet cleaning system. There are some potential safety issues (see below in Primers). Perhaps even more importantly, wet cleaning does not work nearly as well with spent primers in place. Forget ever reusing a batch of cleaning solution; spent primers make a gruesome mess.


E. Lube with Carbide

In theory, you don't need to lube 9mm case when using carbide dies. In practice, several members do lightly lube 1 of 5 or 1 of 10 cases for ease of loading. The 9mm has a taper, and this causes new and/or clean cases to gall the carbide on the upstroke. You can see brass deposits on the carbide. This won't hurt anything at first, but over time it will effect the sizing or scratch the carbide insert. You can either clean the sizing die more often, or use a very slight amount of lube. This is usually only a problem with brand new brass or brass that has been polished by a tumbler.

Depending on which brand of media additive is used, this may not be necessary, because some of them leave a slight film on the cases. Cases cleaned with wet methods generally do not have this problem, either. Dirty cases won't need lube with carbide dies, as the nitro fouling acts as a dry lube. Dirty cases do eventually ruin a die on their own, however.

This is a hint I picked up from Richard Lee's Modern Reloading (1st ed.), page 56. Dilute 1 part Lee sizing lube with 10 parts rubbing alcohol (or water, alcohol evaporates more quickly). Put the mixture in a plant sprayer. Spray some cases with a light mist, let dry, and space them amongst the other cases to be sized. More than one in five is serious overkill.

CZF Member Mr. Phil does essentially the same thing, but he uses Hornady One-Shot case lube, an aerosol. He loads on a Dillon progressive and finds that this is easier on the loading arm. I also find that once the cases dry, some lube does actually speed up the loading process.

Both of these products share an important trait. They are applied wet, but are used after drying. This seems to be the secret to their success. Wet or greasy lubes cause their own set of problems.

F. Summary

Once-fired 9mm cases are an excellent source for cases, but some brands are better than others. Sort cases by headstamp for safety and accuracy reasons. Trimming cases is probably not absolutely necessary, but there are many benefits of doing so. Although the initial expense of a tumbler can be postponed, you need to clean the cases with some other method. Depriming cases prior to cleaning is probably not absolutely necessary, but it is also a desirable practice. Ultra clean cases sometimes benefit from a very small amount of dry lube.


III. Bullets

A. Bullet Materials

There are three basic types of bullet materials for 9mm Luger: jacketed, plated, and lead. The material that the bullet is made from has a greater bearing on performance than its shape.

Jacketed bullets are pure lead swaged into a cup of gilding metal, and most have exposed lead at base. The main advantages of jacketed are as follows: 1) No fouling from lead or lube; 2) The exposed lead will often cause the jacket to obdurate the bore; 3) Jacketed bullets are best for maximum velocities. The disadvantages are as follows: 1) Some copper fouling; 2) Gilding metal wears barrels faster than lead or copper plating. (This is more of a theoretical disadvantage than a practical one.); 3) FMJ bullets are the most expensive to manufacture. Jacketed bullets have a variety of subcategories, such as full metal jacket (exposed lead), full metal jacket (enclosed base), jacketed hollowpoints, and specialized types (i.e. semi-jacketed hollowpoints).

Plated bullets are pure lead bullets that have been electroplated with either copper or a cupro-nickel alloy. The main advantages of plated are as follows: 1) No fouling from lead or lube; 2) No exposed lead at the base, so no airborne lead for shooting indoors; 3) Plated bullets cost significantly less than FMJ bullets, but more than lead. The disadvantages are as follows: 1) Major copper fouling when loaded at jacketed velocities; 2) Minimal obduration (some manufacturers compensate with 0.3555-0.3560" bullets); 3) When reloading, plated bullets do better with data specifically developed for this bullet type, but such data can be hard to find. Many of the Speer premium bullets are electroplated (i.e. Gold Dot and TMJ designs), but the plating used is much harder and higher in copper content than other plated reloading bullets (i.e. Montana Gold, Berry's, and Rainier).

Lead bullets are pure solid lead or lead alloy bullets that have been lubed. These fall into two categories: swaged (pure lead or soft alloy) and cast (harder alloys). Swaged bullets are formed from pure lead or a very soft alloy in a succession of dies; reloaders can also buy swaging dies. Hard cast bullets are made from harder lead alloys that are melted and cast in bullet molds. The primary advantages of lead bullets are as follows: 1) Swaged lead bullets are by far the most economical bullets to manufacture, followed closely by hard cast lead bullets; 2) When the alloy is properly matched to the application, lead bullets are usually the most accurate, as they will fully obdurate the bore. Lead bullets have the following disadvantages: 1) Significant fouling from lead and lube; 2) Potential health hazards, both at the range and at the bench; 3) For all practical intents and purposes, swaged lead bullets cannot be used at velocities higher than 1,000 fps; 4) If the alloy is not properly matched to the pressure/velocity, hard cast bullets will also lead up a barrel at higher velocities. 5) When reloading, lead bullets are less convenient than other types and can make a mess of the seating die; 6) Some brands of lead bullets will lead the barrel no matter what, due to poor designs.

By and large, most experienced reloaders advocate the use of jacketed bullets for new reloaders. I have been reloading 9mm for just over four years, and I still find jacketed bullets to be the easiest to load. Jacketed bullets are easier to seat. Jacketed bullets are considered "normal" in 9mm Luger, so the data is the most developed.

Plated bullets are neither fair nor foul; they do better with data developed for them. Berry's MFG 9mm bullets are typically .356" to compensate for the obduration differences, which means that you must use lead data with these bullets. Rainier bullets are also slightly oversize at 0.3555," but they can pushed a little faster than Berry's. Using jacketed data with Berry's bullets will cause high pressures and major copper fouling.

Lead bullets are typically .356," and they require data specifically developed for them. Many CZ owners do not reload lead bullets. Although many people have obtained excellent results, others have found particular brands of lead bullets that simply will not group. The Hornady swaged bullets should not be loaded. They have a latticework to hold the lube instead of grooves, and the lattice breaks up in the CZ rifling. In addition to the mess, they will occasionally keyhole. Before buying a large quantity of commercial lead bullets, I recommend posting a new thread asking for feedback on that particular bullet. There are too many different issues to cover here.

Any pistol will shoot lead well if the alloy and lube are correctly matched to the load. Realistically, this almost requires casting your own bullets or spending some real time and effort working with a particular make/model bullet. I have had some limited success with resizing and relubing commercial cast bullets with Lee Alox.

B. Bullet Shapes

The bullet shape is sometimes confused with construction, as certain shapes are associated with certain materials. For example, the vast majority of full metal jacket bullets are round nosed. Until recently, most lead 9mm bullets were also round nosed or truncated cone. Plated bullets are a recent development, and they are available in virtually every shape.

Member CZ57 contributed the following chart, which gives the abbreviations for most of the available handgun bullet shapes and types. As this came from a discussion thread, I made a few additions for clarity:

FMJ- Full Metal Jacket
SWC- Semi-Wadcutter, also available jacketed.
FMJSWC-The two combined.
TMJ- Total Metal Jacket, actually an enclosed base plated bullet. (Speer)
RNSWC- Typically lead SWC with a round nose where the bearing surface is true caliber and the ogive is started from a smaller diameter.
DEWC- Double Ended wadcutter.
BNWC- Button Nose wadcutter.
BBWC- Bevel Base wadcutter.
HBWC- Hollow Base wadcutter.
FP- Flat Point, lead or jacketed.
RNFP- Roundnose Flat Point. (Don't ask me who thought that one up.)
TC- Truncated Cone, lead and jacketed.
JHP- Jacketed Hollow Point.
HP-XTP- eXTreme Performance JHP. (Hornady)
FP-XTP- Same with a soft or flatnose.
XTPBT- Same bullet in 9mm 147 gr. with a boattail
FMJBT- FMJ with a boattail. (Hornady)
FMJ-FP- FMJ with a flat nose. (Hornady)
GS- Remington Golden Saber. (another personal favorite)
GD- Speer Gold Dot, JHP; sometimes abbreviated as GDHP.
HS- Federal Hydra Shok, center post JHP
SXT- Winchester Supreme eXpansion Talon; a slightly modified Black Talon.
ST- Winchester Silver Tip ("WST" stands for "Winchester Super Target" powder.)
JHC- Jacketed Hollow Cavity. (Sierra)
X-Bullet - a HP made almost completely of copper, very deadly. (Barnes)

In general, powder selection has a greater bearing on accuracy than bullet shape, at least in 9mm. The main concern with bullet shape is the feeding issues in a semi-automatic pistol. Fortunately, the CZ will fire any reasonable bullet shape and cartridge overall length. (Obviously, it will not feed cartridges loaded with full wadcutters, provided you could find them in 9mm.) In accuracy terms, the CZs do not have a dramatic preference for a particular bullet shape, but fortunately, they do shoot all of them fairly well. Bullet shape does have a major impact on bullet seating (see Techniques below).

C. Bullet Weights

Bullet weight affects accuracy for a number of interrelated reasons. Bullet weight should also affect your loading technique, to some extent.

Rifled barrels have rates of twist, or how fast the grooves make one full 360 degree rotation. In the U.S., this is expressed in a ratio in inches. Thus, 1:16" means that the grooves will make one full rotation in a 16" barrel. 1:9" means that the rifling grooves make a full rotation within 9", which is known as a "faster" twist. At any rate, matching bullet weight to rate of twist is critical in rifles, and it does affect handgun accuracy, even though bullets rarely make one full rotation in a pistol.

All things being equal, heavier bullets have longer bearing surfaces, i.e. more bullet length engaging the rifling. A heavier bullet has to spin faster to stabilize, due to its greater weight and overall length. Heavy bullets fired with too slow of a rate of twist lose momentum and accuracy quickly. Early 9mm pistols had rates of twist that were quite slow, in the 1:12" to 1:16" range, since only 115gr FMJ bullets were available for some decades. CZ 9mms have a faster rate of twist of 1:9.75," which is intended for the 124gr weight, but is fast enough to stabilize 147gr bullets. The "ideal" rate of twist for 124gr is roughly 1:10."

Compared to rifles, handguns are extremely low in velocity, and matching the bullet weight to the rate of twist is not as important. In particular, the short effective ranges of most handguns prevent unbalanced bullets from creating significant deviations caused by too great or too little rotational force. Most importantly, handguns have some inherent features that degrade accuracy and precision: short sight radius, short barrels, light weight, etc. However, it does help to understand that just because 9mm has a wide range of available bullet weights doesn't mean that all will shoot equally well.

CZ 9mm pistols have a faster rate of twist than many other 9mm designs at 1:9.75" (as opposed to 1:10"-1:12," which is more common). This makes them better suited to 124gr and heavier bullets than most other 9mm pistols. This has been an important factor in their success, since most nations began switching over to 124gr bullets about twenty years ago. Commercial loads heavier than 124gr began to appear on the market at about the same time that CZ pistols became readily available in the West. Although 147gr loads are not as accurate in a 9mm CZ as bullets in the 115-135gr range, the CZs handle them much better than some of their competitors.

Most CZF members who reload have obtained better results with the 124gr bullet weight, but it has not been a dramatic difference between 115gr and 124 gr. 124gr bullets typically have longer bearing surfaces than 115gr, which also helps achieve better accuracy. Your first reloading efforts should probably be 115gr or 124gr FMJ-RN for ease of loading and an immediate improvement in accuracy over factory ammunition.

Like the Beretta 9mm pistols, the CZ pistols are known for accuracy with the 147gr bullet weight. However, there are some practical reasons for avoiding bullets heavier than 124gr for your first efforts.

As the bullet weight in 9mm exceeds 124gr, you begin to see a dramatic diminishing return in velocity. Since the bullet diameter cannot exceed .355," the extra weight comes from greater bullet length and a less aerodynamic bullet profile (different ogive). Since the loaded cartridge length cannot exceed the maximum of 1.169," the heavier bullets, which are longer, must displace available case volume. 9mm Luger has no case volume to spare; the available volume is only @0.7 cubic centimeters. All factors being equal, a heavier bullet will travel more slowly with the same powder charge. The problem is that all factors are no longer equal. The case has lost quite a bit of volume, which creates two further complications. 1) It can't hold as much powder anymore. 2) There is less room for the combusting gasses, which quickly raises internal pressures. These factors combine to significantly reduce potential velocity.

The 9mm Parabellum cartridge was originally designed as a 115gr load at @1,200 fps. The 147gr loads are such a radical departure from the original design and bullet profile that they often cause feeding and functioning problems when reloaded. In some 9mm pistols, the 147gr loads have a tendency to cause premature hold open, since the larger bullets often nudge the slide stop. CZs have relatively short chambers, so the reloader cannot "cheat" by loading at or around 1.16" OAL.

Rarely, 147gr loads can cause functioning problems due to their reduced slide velocity. A self-loader requires ammunition within certain ranges of velocity and pressure in order to cycle the action. Velocity is the most important aspect of this equation. As a cartridge fires, its head produces a roughly equal and directly opposite reaction against the breech face, which provides the recoil impulse to cycle the slide. If the velocity drops too low, the pistol can no longer operate correctly. This rarely happens with factory ammunition, but the 147gr loads at modest pressures and low velocities are flirting with the low end of reliability.

D. Summary

To sum up, 115gr and 124gr jacketed bullets are usually the best for learning the cartridge. Plated and lead bullets are good values for the volume shooter, but they are slightly more difficult to load for the novice. Lighter or heavier bullets do not have the same accuracy potential as the middle weights (115 and 124gr). Most self defense loads are in these two bullet weights for good reason. There is no specific bullet weight and/or shape that will compensate for poor powder selection or loading technique.

IV. Powders

A. Introduction

Smokeless powder has several characteristics that affect performance. The two most significant are density and burn rate.

Powder density has two separate meanings to the reloader. Volumetric density is an expression coined by Richard Lee, because "density" can be somewhat ambiguous. Load density refers to how much powder is in the case. Volumetric density is the volume displaced by one grain of a particular powder, or the density of that particular powder. Both are critical, which will be explained below.

Burn rate refers to how fast a particular powder combusts into propellant gases. In general, fast powders are better suited to low pressure loadings. Slower burning powders give higher velocities and more consistent results, especially in higher pressure loadings. Essentially, a slower burning powder also builds pressure more slowly, which keeps the peak pressure lower. This can be critical in order to realize the potential of heavy 9mm bullets. Slower powders tend to yield maximum load density. In 9mm Luger, powder burn rate seems to be the single most important characteristic for top accuracy, assuming correct loading techniques.

B. Powder Density and Volume

The most important property of either blackpowder or smokeless powder is that it also occupies volume in the cartridge case. In other words, one can think of powder in terms of charge weight and/or volume. Charge weight is a convenient way to measure powder, and it is usually the most accurate with current equipment. However, thinking solely in terms of powder weight will limit your results. Consider the fact that all powder measures and similar equipment dispense powder by volume, not weight.

The relationship between available case volume and the volume of the powder is known as load density. A high load density means that there is little or no airspace in the case. A low load density means that the powder occupies less of the case volume, resulting in some airspace. Slower burning powders tend to yield higher load density, because they require heavier charge weights and are "bulky" (lower volumetric density). In other words, the charge weight is heavier (more grains), and each grain also takes up more space as compared to most fast burning powders.


It is very important that the reloader understands the relationship between mass and volume. As the charge weight increases, the load density increases, so there is less airspace. Either factor alone would raise pressure significantly. Obviously, more powder generates more energy, raising pressure. Less obvious is that more powder occupies more space, which also raises pressure, as the expanding gases have less available volume. However, these factors cannot be isolated, and 9mm has a relatively small case. It is extremely important to work up loads properly and safely with 9mm. Certain fast burning powders can cause dangerous pressures with extremely small increases in charge weight.

9mm Luger was designed for use with smokeless powder. In practical terms, this means that most powders intended for handgun use will work in 9mm and yield decent load density. For purposes of comparison, let's look at .38 Special, which was designed for use with blackpowder. Blackpowder has a low volumetric density (a grain takes up more space) and a high charge weight, as compared to the more efficient smokeless powders. This means that .38 Special and similar cartridges (.44 Special, .45 Colt, etc.) have too large a case volume for many smokeless powders. .38 Special is also low in pressure, which means that a faster burning powder will be required. Faster powders use lower charge weights and yield a low load density. All this adds up to a problem. Typical .38 Special charges are less than 4 grains of powder, creating far too much airspace. Low load density of this type can cause major problems. If the powder is strung out through the large case, it may not all ignite at the same time or at all. If it does, it will burn unevenly, more like a fuse. Powder may not even contact the primer at all.

Again, this is never a major concern with 9mm, as the case volume is so small, less than 0.7 cc (cubic centimeters). Fortunately, this also means that it is fairly easy to find an optimal load. A higher load density, or even slight compression, tends to yield better accuracy with extruded powders. The powder position issues discussed above are not a factor. Since 9mm is a fairly high-pressure cartridge, or 35,000 psi max SAAMI standard, it is better suited to medium to slow burning powders. This means that maximum load density (little or no airspace, no compression) is obtainable with most powders commonly used in 9mm. The only downside is that 9mm is so flexible that handloads developed using faster powders will still shoot better than factory ammunition, and many reloaders do not experiment with the slower powders more suitable for the cartridge.

Nobel-Vectan ball powders must never be compressed. There must be some airspace in the cartridge case even if it is only the infinitesimally small spaces between grains of powder. Nobel-Vectan specifically warns against compressing their ball powders, as their smaller spheres will pack too densely. Instead of igniting consistently, the primer drives the charge like a piston, which can create dangerously high pressures. 9mm data using ball powder will sometimes seem artificially conservative; this is because some publishers also do not list compressed loads. In particular, I have noticed that Winchester no longer lists compressed loads with W-231. Extruded and flake powders can be compressed, and accuracy may even improve with slight compression. The shape of the powder prevents it from packing tightly into the case.

With extruded and flake powders only, maximum load density or slight compression can even provide an added safety margin. For example, Alliant Unique and IMR SR 4756, which are medium and medium-slow burning extruded powders, will yield near maximum load density at typical factory velocities. Max load density will yield velocities and pressures higher than factory ammunition, and slight compression yields a lower end +P cartridge. With these two powders, the 9mm case cannot hold enough powder to exceed +P maximum pressure in the midweight bullets, no matter how hard you try. This means that a dangerous overcharge is impossible; the case just can't hold enough powder. Max load density does not permit the bullet to set back when it hits the feed ramp; there is no space. Compression can sometimes cause "bullet creep," as the compressed powder returns to its original shape, forcing the bullet to creep forward from the case. A firm crimp can overcome this problem. A load at or just under max load density will not creep, no matter which type of crimp is used.

Remember, Nobel-Vectan ball powders must never be compressed.

C. Powder Burn Rates

Before proceeding, it may be helpful to consult the following link:
"http://www.reloadbench.com/burn.html"
This webpage provides some definitions and a burn rate chart to which I will refer.

The Norma Reloading Manual contains an article on smokeless powders written by Sven-Eric Johansson of Nexplo/Bofors. I mention this because it is by far the best treatment of the subject I have ever seen; it even includes photographs detailing every step of the manufacturing processes.

Mr. Johansson defines burn rate as follows:
"The linear burning rate of a propellant is the rate at which the chemical reaction progresses via both thermal conduction and radiation. The burning rate is equivalent to the distance (normal to the burning surface of a powder grain) burned through in a unit of time. This varies not only with composition, pressure, temperature, and physical structure of the powder (i.e. porosity,density), but also with the shape of the powder grain. Powder with a high calorific value burns faster than powder with a low calorific value" (102).

Due to their higher calorific value, fast burning powders also tend to produce more heat as a form of wasted energy. There is a direct geometrical progression between maximum chamber temperature and burn rate as the burn rate increases (becomes "faster"). Environmental factors such as ambient air temperature and relative humidity also affect burn rate. Ammunition generates higher peak pressures on hot, dry days by increasing the powder's burning rate. Leaving loaded cartridges in direct sunlight has a similar effect.

In ballistic terms, the slowest practicable powder will generate more uniform internal ballistics, lower chamber pressures, lower chamber temperatures, and higher velocities. Slower powders require heavier charge weights and often have a low volumetric density. To clarify, this means that the heavier charge is also relatively bulky, because one grain of the powder also takes up more space. Some powders are too slow burning for 9mm, because the case cannot hold enough of that particular powder.

The working pressure of the cartridge is the most important factor in selecting the correct burn rate. A higher peak pressure equates to a slower burn rate. 9mm has a relatively high peak pressure for a handgun cartridge: 35,000 psi SAAMI and 38,500 psi SAAMI +P. This means that the slower burning powder can combust more slowly and build pressure in a slow, uniform, geometric progression. This allows for more gradual and complete acceleration at a lower relative pressure and temperature. Conversely, a low pressure cartridge like .38 Special requires a faster burning powder with a higher calorific value. Slower powders will not ignite and combust evenly at such a low working pressure.

By consulting the burn rate chart at "http://www.reloadbench.com/burn.html" and comparing it to your reloading manuals, you will make some immediate observations. Although you will find published loads using Norma R-1 (#1, the fastest burning powder) to Alliant 2400 (#67, extremely slow for handgun applications), the vast majority of the published loads use the powders in the #6 to #63 range, or Alliant Bullseye to Accurate Arms No. 9. I personally recommend nothing faster than #20, Winchester Super Target. I have obtained my best results with powders in the #35 to #60 range, or Alliant Unique to Alliant Blue Dot. Due to their properties, powders in the #20-#60 range will all yield acceptable load density and velocities equal to or higher than factory ammunition.

These statements are all generally true, but some powders have peculiar characteristics. For example, Alliant Unique generates relatively high chamber temperatures for its burn rate. Universal Clays, which is theoretically identical to Unique, does not generate as much heat, but tends to generate a higher peak pressure. Unfortunately, this can be load or cartridge specific, and you will have to learn by experience which powders will work best in your particular pistol. However, this is half the fun as well.

In summary, best accuracy in 9mm Luger is usually obtained by using a medium to medium slow burning powder that allows for a high load density. With a Nobel-Vectan ball powder or any powder with exceptionally small grains or spheres, some airspace is desirable for safety reasons. With an extruded powder, maximum load density (little or no airspace) or even slight compression usually yields the best accuracy at a velocity higher than most factory loadings.

D. Other Considerations

The above section is an oversimplification, because one cannot select a powder based on burn rate and load density alone. Powder manufacturers deliberately alter the characteristics of powders by adding deterrent coatings, decreasing volumetric density with cellulose, etc. to provide the reloader with more options. A brief discussion of some of the other considerations follows.

Availability is obvious, but often ignored by some. A casual glance at the burning rate chart reveals that several of the optimal 9mm powders are manufactured by VihtaVouri (Finland) and Nobel-Vectan (France). Odds are, you may not be able to walk into the corner gun store and buy these in 1 lb. canisters.

Economy is a major factor for many. Slower powders use heavier charge weights, and powder is sold by weight, not volume. Some of the slower handgun powders, such as Alliant Blue Dot, also cost more by the pound than other powders.


Metering is a major concern for most 9mm reloaders, because they shoot so many cartridges in a month. Metering refers to how well equipment can uniformly dispense the powder. Ball powders meter extremely well, because the spheres are so small and uniform. Older extruded and flake powders do not usually meter well.

Cleanliness is a major concern for some shooters; some could not care less. Generally, selecting the correct burn rate will equate to a complete and clean burn. Some powders, such as Unique, are relatively sooty despite this fact.

Pressure curves have not been discussed much thus far, because they are theoretically tied to the burn rate. Some powders build pressure relatively quickly for their burn rate. These powders are poor choices for lead bullets, because they often generate higher heat as well. These factors may combine to deform the base of the bullet. Some shooters notice differences in felt recoil when shooting maximum loads with these powders. Alliant Green Dot is an example of this type of powder.


E. Some Thoughts on Powder Selection

The following comments come from an older thread on 9mm powder selection. These were provided by jwc007 and CZ57, and I have selected these because they articulate two slightly different approaches to powder selection. I have edited them somewhat for clarity.

jwc007 :

"Some fast burning powders (Red Dot, N320) have a very gradual pressure curve, allowing them to be used some in higher pressure (9mm) cartridges. They will of course pressure peak quicker, but sometimes at the point where maximum desired energy (velocity) has already been produced (target loads), and anything slower would be a waste and not produce enough pressure to seal the chamber at the point of ignition, and foul the inards of the pistol (blowby).

Slower propellants are best at least loaded to 80%, or at most 95% of maximum, to produce efficient burning and desired higher energies.

Not all slower burning powders have a gradual pressure curve and Universal is one that has a rather abrupt one. According to the Hodgdon Load Data Chart, Universal is more useful in the larger .40 S&W than the smaller 9mm.

The often ignored Mid-Range Powders (Green Dot, WST, N330) are more useful in producing average 9mm commercial velocity results with not a lot of waste. Actually, N330's gradual pressure curve will get you some performance as well, but not as much performance as 3N37 or 3N38."


CZ57:

"jwc007, I agree with you that burn rate is not the whole story, but it shouldn't be ignored. Neither should load density. I don't consider Green Dot, WST or N330 to be the often ignored range of powders. On many forums, you will see much more powder in this burn rate being used than you will AA#7, VV3N37, or even HS-6 for the 9mm. I don't believe Red Dot, WST or N320 to have gradual pressure curves. Typically target loads using these powders are experimented with until one finds the accuracy they desire and usually it is found at their optimum pressure. A pressure curve chart should be consulted when assessing pressure curve and pressure peak, because what I think you are looking at is the total pressure operating range from beginning to peak.

Faster burning powders in the rate you are describing may range from 20,000 to 38,500 psi, but that is not the entire story of the curve. The specific chart I am using is from Ramshot describing a moderately fast powder (ZIP, like WST, Green Dot, N330). What it is really showing is the fast rise in pressure vs. light powder charge weight, approx. 3.0 grs. to 5.3 grs. That is a differential of 18,500 psi with only a 2.3 grain charge increase with its optimum between 30,000 and 34,500 psi that occurs between 4.7 and 4.9 grains. If I set out to build an accuracy load with this powder, obviously I would expect to find it in the 4.7 - 4.9 gr. range, but it's already operating in the 30,000 to 34,500 psi range. Much closer to maximum standard pressure for the 9mm. The curve would indicate where pressure begins to rise significantly from the recommended origin, to the point where velocity gain decreases and pressure still rises.

Look at the medium powder (Silhouette, slightly slower than Unique or Universal and similar to HS-6, WAP, N340, W-540 and WSF) in it's recommended range of 25,500 to almost 35,000 psi, it is rising considerably slower from beginning to peak, True, the powder weight change is only from 5.15 to 6.15 grs but the pressure rise is considerably slower from beginning to peak pressure with the optimum range from 29,500 to 32,500 psi, or 2000 psi less than ZIP. However, from optimum pressure to peak pressure the pressure spike is considerably less drastic, even if you cut ZIP off at 34,500 psi.

Then there is the even slower burner (True Blue, like 3N37, AA#7), 6.15 grs. to 7.0 grains with no mentionable spike throughout its range that is much more gradual from 28,000 to 34,000 psi. That would indicate that the optimum window could be over a much broader range and the rise from 32,000-34,000 psi is very uniform from 6.5 to 7.0 grains. Bulk density is much better and this powder will give sub 10 standard deviation."

FEG:


As you can see from the above comments, the approach really depends on what your goal is. If you want to load high performance 9mm ammunition, you will need to use a slower, modern powder with a gradual pressure curve. If your goal is to assemble accurate ammunition of a particular velocity (i.e. to make Minor PF) and do so economically, a faster powder with a higher calorific value and lower charge weight may be adequate.

When compressing an extruded powder, you are essentially wasting some powder to gain uniformity. The minute cartridge to cartridge variations do not factor into the equation, because only X amount of powder ignites.

I would further add that WST is an excellent powder for duplicating factory ammunition for the volume reloader, even though it is a little faster burning than I typically load. It delivers near max load density (0.66 cc). It is not optimal in terms of pressure curve or potential velocity, but this is the type of powder you will find in many commercial loadings. WST is deliberately designed to yield a higher load density than a ball powder with this burning rate would "normally" have.

F. Summary

Smokeless powders have several characteristics that influence performance. The most important are powder density and burn rate. Medium to medium-slow powders usually give the best performance in 9mm Luger, due to its high working pressures. Faster burning powders may be more efficient for certain types of loads, but their use limits potential velocity. Higher load density usually gives better results in this cartridge, but Nobel-Vectan ball powders must never be compressed. A burn rate chart may be helpful in selecting a powder, but it does not provide the entire picture, as factors such as availability, economy, and load density should be considered as well.


V. Primers

A. Primer Types and Characteristics

Unlike smokeless powders, which are merely propellants, primers are in fact mild explosives. Primers should be stored in their original packaging and handled in small quantities when possible. Handling primers is by far the most dangerous aspect of reloading, but it is perfectly safe when done according to the manufacturers' instructions.

A 9mm reloader is only concerned about one type of primer: standard small pistol. Overall, consistent primer seating is the goal; other considerations are always secondary. Since most people will eventually load for other cartridges, it might be helpful to briefly outline the basic primer types and characteristics.

There are two basic primer designs: Boxer and Berdan. In the United States, the Boxer system is used for 99.9% of all military, factory and reloaded ammunition. The Berdan system is popular for commercial ammunition overseas, but the Berdan system is primarily associated with military ammunition. Boxer primers are self-contained; the primer is essentially an anvil surrounded by a cup of priming compound. In the Berdan system, the anvil is part of the case. Boxer cases have a single flash hole is the center of the primer pocket. Berdan cases have two or more flash holes near the edge of the pocket; the center of the pocket is a metal nipple that acts as an anvil. Occasionally, you will hear people say that Berdan cases are not reloadable. This is not strictly true, but the equipment to reload Berdan cases is highly specialized and expensive.

The following discussion is therefore limited to Boxer primers. Boxer primers are classified by their size, application, and power (standard or Magnum).

Regardless of their other characteristics, Boxer primers only come in two diameters: small (0.175") and large (0.210"). Another way to look at this is that primer pockets only come in two diameters: small and large. Handgun cases up to and including .40 S&W use small pistol primers. Starting around 10mm, .41 Magnum, and up, large pistol primers are used.

Although they are the same in diameter, pistol and rifle primers are very different. Rifle primers are designed for much higher working pressures. They have a hotter burn and thicker primer cup, which actually degrades performance in a handgun. Rifle primers should never be used with 9mm, the case is far too small for the higher pressure that the rifle primer will generate. More likely than not, the primer will not ignite (handgun firing pins are too light), and if it does, a dangerous pressure situation will result (too high or too low).

Finally, primers come in two versions: standard and magnum. This distinction is often misunderstood. For example, all .357 Magnum loads do not use small magnum pistol primers; in fact, the vast majority use standard primers. Magnum primers have a hotter burn, and they are intended for use with certain slow-burning powders to help provide more consistent ignition. Normally, magnum primers actually degrade performance unless the data specifically calls for their use. Powders suitable for 9mm either will not benefit from a magnum primer or will not benefit enough to justify the added expense.

B. Primer Brands

Any theoretical difference in accuracy that one brand may offer over another is much less important than how well they seat in a particular brand of 9mm case. Some makes and models of equipment operate better with certain brands of primers. As this is somewhat beyond the scope of this article, I recommend starting a new thread asking owners about particular priming systems as needed.

Winchester standard small pistol primers are the most commonly used in 9mm. They will work in all or most makes/models of equipment, and they fit well in most brands of cases. Winchester primers are typically the least expensive. The correct Winchester primer for 9mm is WSP ("Winchester Small Pistol").

Remington standard small pistol primers are considered less desirable than Winchester by many, but they are virtually identical in performance. Remington primers are not as well distributed as Winchester; only Remington shotgun primers are available in my area. I have noticed other reloaders in the Midwest and Midsouth making this comment. The correct Remington primer for 9mm is # 1 1/2.

CCI standard small pistol primers are slightly larger than all other brands. Speer and CCI cases have correspondingly larger primer pockets to match. CCI primers are most useful when reloading Speer/CCI cases or older cases with loose primer pockets. The general consensus is that CCI primers are somewhat milder than other brands. I am not sure if this is due to their construction or a side effect of being forced into primer pockets. CCI primers have a nickel coating that helps with feeding in some priming systems. CCI primers typically cost more than Winchester and Remington, but less than Federal. The correct CCI primer for 9mm is #500.

Federal primers use an older priming formula known as "basic compound." Basic is easier to ignite and has higher brissance (flame) than the modern formula in Winchester, CCI, and Remington. I would imagine that some of the primers made overseas might also use basic compound. You will sometimes hear people claim that the Federal primers have a thinner primer cup. This is not true; they are easier to detonate due to the priming compound. (See Lee's Modern Reloading for more information on the priming compounds.)

The main advantage of the Federal primer is a slightly hotter and brighter burn. This is very important for consistent ignition in certain powders. I use Federal primers almost exclusively when loading older flake powders in the medium to medium-slow range with certain cartridges. I have had better accuracy results in 9mm with Alliant Herco using Federal standard small pistol primers, but I have not seen any appreciable advantage in 9mm otherwise. I would advise the use of Federal standard small pistol or their Gold Medal Match standard small pistol primers when a hotter burn is deemed necessary. The correct Federal primers for 9mm are #100 and # GM100M (Gold Medal Match). Match primers are slightly hotter still, but do not generate as high of a peak pressure as a true magnum primer.

The biggest downside of Federal primers is all that comes from the easier and hotter ignition: slightly higher pressures and more accidents. Federal primers will raise pressures slightly, but they do not usually increase velocity. Several manufacturers advise against using Federal primers with their equipment. Federal primers are typically the most expensive. Gold Medal Match primers are even higher at an additional $2-$3 per thousand.

Magtech also offers component primers, which are slightly less than Winchester via mail order, but they are not widely distributed in retail stores. I have no specific information on the Magtech primers at this time. Magtech/CBC loaded ammunition, component brass, and bullets are all quite good, so the Magtech primers are probably a good buy as well. By the way, primers are the most critical and difficult component to manufacture; be wary of "bargains."

RWS and Hirtenberger are European firms that manufacture high quality primers. Their products are only available on a limited and infrequent basis in the United States. Often, the RWS and Hirtenberger primers that are imported are Berdan, not Boxer (both companies offer both basic types). I would avoid these brands, but only due to their expense and supply problems. The correct RWS primer for 9mm is #4031. The correct Hirtenberger is #1206.

For the vast majority of 9mm loaders, Winchester standard small pistol primers will handle all of your needs at a lower cost. In perfecting certain types of loads, experimenting with primer brands may be beneficial. However, switching primers will usually degrade a near-perfect load, as it was virtually perfect with the other brand of primer and could not be readily "improved." Generally, a major increase or decrease in group size when switching brands indicates that your equipment works better with one brand. Remember, consistent seating is much more important than brand names.

C. Primer Seating

Consistent primer seating is absolutely critical. Considering the wide array of available brands and options (i.e. bench rest and match primers), the novice may believe that the secret is selecting the correct brand or model for the load. In handgun cartridges, this is rarely a critical factor, while primer seating is often misunderstood.

There are two issues with primer seating: safety and accuracy.

High primers may cause slamfires and other dangerous conditions in a semi-auto. (They will also bind revolvers.) Low primers may be crushed and ignite unpredictably, even causing squib loads.

From an accuracy standpoint, seemingly minor inconsistencies are extremely important. If the primers are not 100% seated, a portion of the hammer blow actually seats the primer before or during ignition. This ruins your group and usually causes vertical stringing. No two cartridges ignite identically, which prevents top accuracy.

From a safety and reliability standpoint, primers must be seated so that they are at least flush with the case head. From an accuracy standpoint, primers must be fully seated, which is slightly below the case head. The exact measurement will vary according to the components, assuming you have a micrometer. Calipers are not practical for measuring seating depth, IMHO. Generally speaking, you will be able to obtain good results by feel or simple consistency (all primers seated 95% is better than a range of 96-100%).

D. Safety Concerns

As was mentioned above, primers are the most dangerous component. A primer contains an explosive, while smokeless powder is merely a propellant. Always follow all of the manufacturers' safety recommendations when handling primers. If you do not wear eyeglasses, wear safety glasses. I have been reloading for over four years, and my father has been reloading for over thirty years. Neither one of us has ever had a primer detonate while loading nor had a gun damaged by a handload. However, we both follow standard safety practices, which are outlined in any reloading manual. Reloading is not dangerous, provided you have the temperament to follow instructions.

There is another safety concern with primers that is much less understood: lead styphnate. In general, the shooting public is aware of the dangers of airborne lead. The main concern with vaporized lead is that the body can absorb lead in several different ways. Lead inhalation causes greater absorption than contact with the skin. In fact, lead poisoning through the skin is virtually impossible, but there are always concerns with cross-contamination (eating with lead on the hands, etc.).

Primers use lead styphnate as a binder and base for the priming compound. This is more or less inert before the primer is detonated. The black granular material left over inside a spent primer is almost entirely lead styphnate, because the explosive materials are consumed. This material is highly dangerous, because it easily breaks down into a dust that is readily inhaled. Most shooters never handle spent primers in gigantic quantities; 9mm reloaders often do.

I highly recommend the use of a dedicated decapping die. My routine is as follows. Cases go straight from the ground to an old plastic shopping bag. When I get home from the range, I more or less go straight to the decapping die and deprime all of the cases. The spent primers go into the same plastic bag, which is usually pretty nasty by now. The bag goes straight into the outside trash. I go straight into the shower, unless I have some serious gun cleaning to do. This gets the majority of the problem out of my home as quickly as possible, and it seems to prevent the lead styphante from getting into the cases as much. You may have noticed that dirty cases that sit for a while get dirtier; this is the styphnate breaking down and getting all ove