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slightly confusing.

Information on reloading for precision or money saving, equpiment to use, powder and primer suggestions, all welcome

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05roadking
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slightly confusing.

Postby 05roadking » Fri May 16, 2014 2:18 pm

I just started reloading, or should I say attempting to reload. It seems the data can vary from powder to bullet manufacturers. Is there a bible for reloading? I got the sizing, decapping, cleaning and priming down. I've done you tube hell for hrs., still not sure about crimping. any help would be great.



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CTSixshot
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Postby CTSixshot » Fri May 16, 2014 2:50 pm

You can probably find the basics online, as well as in books like Lyman's Reloading Manual, etc...
http://www.lymanproducts.com/lyman/publ ... dition.php
There is conflicting data out there. Some manuals tend to list lighter loads, probably to ward off any liability issues. Not every bullet will be listed in every manual, so you have to use a bit of intelligent guessing. If this isn't suitable, stick to published data with known components.
Crimping, in short, is subject to what you're doing and have done, IOW,. if you've flared a .45 ACP case to allow for lead-in with cast bullet seating, you will use a "taper crimp" to return the mouth to proper dimensions. Auto-loader pistol calibers generally headspace on the case mouth, so they don't get a "roll crimp" (like most revolver cartridges that typically headspace on the case rim). I generally taper crimp all but the stoutest revolver cartridges.
There's much more, but I'm not going to type volumes....
...you're welcome to come down and sit in with me and discuss specifics. I use a RCBS RC, but the fundamentals apply to most issues. We can reload and shoot on-site.
Last edited by CTSixshot on Fri May 16, 2014 7:11 pm, edited 2 times in total.

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Skinnedknuckles
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Postby Skinnedknuckles » Fri May 16, 2014 3:45 pm

This is my opinion on crimping for handgun cartridges, so please take it for what it is worth. It works for me, but you have to develop your own reloading processes.

The purpose of crimping is different for revolvers and for semi-auto's. For high power (high recoil) revolvers, the dynamic forces of recoil tend to cause the bullet to "walk" out of the case, like a dynamic bullet puller. If this happens enough, the bullet nose will extend out of the front of the cylinder and prevent the cylinder from turning. This happens most with high power cartridges in light handguns - think .357 Magnum in an alloy frame snubbie. In this case, the primary thing keeping the bullet in the case is the crimp, and a heavy roll crimp is a necessity (and may not be enough, in extreme cases). If the cartridge is relatively mild and in a heavy framed revolver - think .38 Special wadcutter target ammo in a Ruger GP-100 with a 6" barrel - the bullet is not going to walk out even with no crimp. Since revolver cartridges typically headspace on the rim, crimping is just for bullet retention and to insure it fits in the chamber.

In semi-automatic pistols, recoil tends to drive the bullet back into the case, just the opposite of a revolver. Neck tension (interference fit between the case and the bullet) prevents this from happening, so you want to do the least case expansion possible while still being able to seat the bullets without shaving the bullet. Crimping has little or no appreciable effect on bullet retention in this case, as the neck tension force on the bullet is much greater than any force generated by a taper crimp. Taper crimping is used because a semi-auto cartridge headspaces on the cartridge mouth and a taper crimp removes the bell mouth done for bullet insertion while keeping the cartridge mouth square to the chamber. You only want to taper crimp to the point where the case mouth diameter is slightly less than the case diameter. Too little and it may catch and jam during feeding or not even fit in the chamber. Too much and it will miss the headspace counterbore and go too far into the chamber, resulting in too much headspace and mis-fires or worse. The best rule of thumb I've found is to crimp until the case mouth is about .004" under the case diameter.

For revolver reloading, when I am developing a load, I verify that I have enough crimp by loading a full cylinder, shooting all but one, and measuring the overall length of the last one to see if it increased. If it doesn't, I do the same thing again, and if it doesn't significantly change after enduring two full cylinders of recoil, I figure it is enough.

For semi-auto reloading, I do the "thunk" test by dropping test cartridges in the chamber (take the barrel out of the gun for this) like a cartridge gauge. If it freely drops into the chamber and audibly hits the headspace counterbore, then I test feed and chamber samples at the range for function. If they pass the thunk test and function smoothly, I figure I've hit the sweet spot, and that .004" rule of thumb seems to work well.

Good luck and welcome to reloading. Shut off the YouTube and load and shoot some ammo.

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05roadking
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Postby 05roadking » Fri May 16, 2014 4:04 pm

ctsixshot, that's a generous offer, I'd like to take you up on that. when and where? Ernie

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Postby CTSixshot » Sun May 18, 2014 1:34 pm

05 RoadKing:
Now that you've got a clearer perspective on things, what "Skinnedknuckles" wrote is probabl;y much clearer now.
BTW, your 7.5 cast shots were all in the lower portion of the "B". An extreme spread of 1 5/8" Those buggers seem to fly pretty straight and true.
Good job on all you did!

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05roadking
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Postby 05roadking » Mon May 19, 2014 5:55 am

Much more clear. Thanks for all your help and incite. It defiantly cut down on the trial and error part of the learning curve. Again thanks


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