.45 acp/auto rim and plated bullets

[David Sinko]

I never had a problem with plating separation in any of my 625s or any other .45 ACP. I still have some plated 300 gr. FP bullets loaded into the .44 Magnum. I'm pretty sure they are Frontier but I loaded them a long time ago and nobody seems to make a plated 300 gr. bullet for the .44 Magnum anymore. There was no cannelure on the bullet and I used a light roll crimp. Velocity is fairly moderate and they are very accurate. I killed a deer with one last year in the Rossi 92 and got complete penetration on a broadside shot. Over the years I've had some very good luck with plated bullets and some very bad luck. You never know until you try.

 

[Nevada Ed]

The last time that I saw a manual actually list a crimp on a 9mm pistol
125 Gr soft point bullet, dia, .355 was in my old "Atomic" Speer #8,
where the bullet, actually had a Heavy, Factory crimp grove on it's bullet.

A heavy crimp on a "Pistol" case rim, may cause problems in the chamber area,
if the case, by passes, the factory drilling, spec's in the chamber.

Lots of "Dummy" cases in crimp pressures, are needed, in most trials,
to give 100% slide & firing pin settings, for your pistol.

 

[Chuck Edwards]

That will work fine on a .38 Special as it headspaces on the rim. However a rimless round like the .45 ACP headspaces on the case mouth.

If you roll that mouth over with a roll crimp you’ve now created excessive head space. In most cases the cartridge is now held back against the firing pin strike by the extractor gripping the rim. which is now what is effectively providing the head space, and it’s still going to be excessive.

In an autoloader, you're correct. In a revolver using AR brass or moon clips, roll crimps are fine since the round isn't headspacing on the case mouth. My M22-4 subsists on a diet of coated 225-grain RNFPs in .45 ACP brass with the case mouths crimped into the crimp grooves, loaded into full moon clips.

 

[StrawHat]

With proper neck tension, merely tapering the flare out of the case will hold the bullet securely.

A crimp, especially anything beyond a light taper crimp, merely shortens case life.

Kevin

 

[smoothshooter]

I see dire warnings about over-crimping plated bullets. How much taper-crimp should be applied to these bullets before the danger point is reached? I just want enough crimp to prevent the bullets from creeping forward under recoil in a .45acp revolver, specifically a Model 25-2.

Taper crimping will not cause any problems.
Roll crimping, by it’s nature, turns the sharp edge into the bullet’s plating, and increases the remote possibility of bullet plating being penetrated by the brass case mouth.