Crimp On .38/.357 Reloads
This is a discussion on Crimp On .38/.357 Reloads within the Reloading forums, part of the Defensive Ammunition & Ballistics category; I have only reloaded auto pistol cartridges thus far, however I recently decided I would begin reloading revolver cartridges as well. The first will be ...
Post By bmcgilvray
January 1st, 2012 12:32 AM
Crimp On .38/.357 Reloads
I have only reloaded auto pistol cartridges thus far, however I recently decided I would begin reloading revolver cartridges as well. The first will be .38/.357. I ordered the dies and some Rainier copper plated bullets. I requested the die set with a roll crimp die, however I didn't take into consideration that the Rainier bullets do not have a cannelure. I assume this means that I will need to use a taper crimp, so I will go ahead and order it. My question is how tight a crimp should I try to achieve?
Thanks for your guidance.
January 1st, 2012 01:27 AM
The roll crimp will work fine with the copper plated bullets, just as it would with lead bullets. The plating isn't so thick that it will interfere with the normal crimping operation. The taper crimp die you ordered will work but isn't required for the copper plated bullets.
You'll want a firm crimp to keep the bullets where they belong, seated to the depth you have chosen, rather than jumping their crimps and backing out of the cases where they can tie up the revolver. What you don't want is to adjust for a crimp so tight that you are cutting brass shavings from case mouths, shavings from bullets, or wrinkling or even partially collapsing case walls. If the case mouth is slightly rolled into the surface of the copper plating that will be sufficient.
If you have a handy factory lead round nose .38 Special load, observe its appearance and adjust your dies to duplicate the factory load's appearance. As you probably already know, uniform case length will translate into a uniform crimp.
You certainly desire adequate crimp. In my early handloading efforts I once deliberately experimented with as little crimp as possible just to see what I could get away with. Sure enough I tied up the revolver with a bullet that had backed out of its loaded cartridge case due to recoil and was protruding from the front of the cylinder, hitting the side of the barrel shank as I thumb-cocked the revolver. No big deal as I just pushed the bullet back into the chamber. I then shot the rest of that box of ammunition off by singly loading each cartridge. It got rid of the ammo and was fine for the rural plinking session I was enjoying but not ideal for ammunition intended for serious purposes. This was with a Smith & Wesson K-Frame .38 Special and a 158 grain lead round nose bullet handloaded to mimic standard velocity factory stuff. It goes without saying that attention to placing a firm crimp on bullets is beneficial when really heavy handloads are used. Heavy recoil moves the revolver and cartridges in its chambers violently enough that bullets' weight has enough inertia to turn the revolver into a rather effective bullet puller.
In the olden days when .38 Special target revolvers ruled bulls-eye competition, very light "powder puff" wadcutter loads, made up with minimum charges of very fast burning powders, were popular. Some competitors swore by using such loads with no crimp at all, only taking care to adjust the dies to remove the flare from the case mouths that is formed to facilitate bullet seating. I've shot such loads produced by others and never had a bullet jump but they are very light loads. Personally, when making a batch of such loads, I generally use 2.8 grains of Bulls-Eye powder and 148 grain hollow-base wadcutters and I adjust for just a hint of crimp with these loads in the interest of insuring that the bullets stay put.
I suppose it would also be possible that an uncrimped bullet could end up pushed farther into a cartridge case. If the bullet is shoved down onto a charge of Bulls-Eye or other powder with a really fast burning rate, a pressure event could develop.
You'll figure all this out the first time you experiment with the crimp adjustment and afterward will have an understanding of the crimping operation that will serve you from now on.
Charter Member of the DC .41 LC Society "Get heeled! No really"
“No possible rapidity of fire can atone for habitual carelessness of aim with the first shot.”
Theodore Roosevelt, The Wilderness Hunter, 1893
January 2nd, 2012 05:33 AM
Thanks much for the information. I have been shooting my revolvers more lately and it didn't make sense to keep buying factory loads. I was concerned that the copper plating on the Rainier bullets, along with the fact that they don't have a cannelure would preclude the use of a roll crimp. It's good to know that it won't create a problem. I'll experiment with it until I get the best results.
January 3rd, 2012 12:46 PM
As noted, the roll crimp works fine. My only caution is to not over-crimp. If you cut into the plating too much is will screw up accuracy.
Chose a weapon that goes bang EVERY time!
January 3rd, 2012 01:32 PM
my friend and i have reloaded and shot over 500 38/357 rounds in the last two weeks. 158 grain cast with 4-6 grains of Unique
we do not crimp anything besides slightly removing the flare because it is simply target ammo and i have had no problems shooting 12 shot 2" groups at 7 yards at a rather quick SA pace
no issues here on anything rattling loose or getting pushed further in during transportation which involves a lot of bouncing around on fireroads to the range
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