How to measure a roll crimp?

[Shrinkmd]

"...3.5 gr Bullseye charges..." Shouldn't need any crimp.

I hope so!

Maybe a better, related question is: Do 38 or 38+P rounds really need much crimp at all (beyond removing the expansion for bullet seating)?

Obviously .357 loads are a different story, but I'm not making those up yet. One step at a time. But soon.

 

[rcmodel]

It all depends on what gun you shoot them in.

Little .38 Spl airweight guns need a heavy crimp.

Ruger Blackhawks & N-Frame S&W's shooting .38 Special?
Not so much.

In general a crimp serves two purposes.
1. To prevent bullet pulling in light and/or hard kicking guns.
2. To get better powder ignition when using large charges of slow magnum powders.

A light charge of easy to ignite Bullseye powder in a 3 pound gun needs no crimp at all.


To find out for sure:
Mark around the bullet/case joint with a Sharpie pen.
Then shoot a couple cylinders full of that load without shooting the marked one.

If the bullet creeps out past the mark, you need a firmer crimp.

rc

 

[Shrinkmd]

Good point about what you're shooting them out of. I plan on shooting from all steel frames, no airweight for me. So hopefully it will not be a problem.