How do you know you have enough crimp? loading 255gr lead for 45 colt staying under 24,000 psi! Thanks for any help....ozzie
I just measured some of my 45 Colt loads with a caliper. Most of my Cast bullet loads are crimped "about" .020 the best I can tell. I can't measure any jacketed loads, I don't use them. I actually don't normally measure the crimp, I just kind of know what it takes if that makes any sense. I guess a rule of thumb would be to crimp until either the case or the bullet starts to deform, then back off a little. Sorry I can't be of more help.
That's something I've wondered or the last 15 years or so. How much crimp is correct?
I've just done it by feel and made sure the case mouth was "bumped" into the crimp groove. Of course, some crimp groove are larger and deeper than others depending on the bullet.
I've gotten by, as have others, but if anyone had a scientific method for measuring and applying a roll crimp to revolver cartridges, I'd sure like to hear it.
I can tell you when you have too much crimp, that's when your case mouths start cracking after a few loadings.
IMHO more important than crimping is a case that is sufficiently sized for proper bullet pull. A mid level 45 colt load isn't going to be pulling bullets out of the case and tieing up the cylinder so long as you have sufficient bullet pull so don't go crazy with the crimp.
take a loaded round in your hand.
push the nose of the round against something firm, wall floor etc...
try with all of your might to push the bullet into the case.
if you can't you're good to go.
one of the things i have been doing, right or wrong, is measuring circumbrance of the projectile inside the case after crimping, and then comparing to what the factory circumbrance diameter would be. trying to match the factory load.
Then pushing them into a hard surface to see if they move.
Always done it just by feel
Read in Handloader (I think) a while back where maybe Brian Pierce stated to run fingernail down from bullet over crimp and when nail doesn't catch/drag on end of case anymore crimp about right
don't try to match the factory outside dia of your ammo. You are SURELY sizing your projectiles down that way.
Cast should be .001 or .002 larger than bore dia.
Factory stuff won't be.
Cast should be .001 or .002 larger than bore dia.
Diameter could end up as such (and probably will be), but strictly speaking, diameter should match the throat diameters of the cylinder no matter what the bore/groove diameter is.
Like others have suggested, I have always set my seater/crimp die by eye. I seat the bullet so that there is approx. .005" between the end of the case and the top of the bullet's crimp groove. I back the seating stem off and screw the die down until the crimp looks good and then run the seater stem down till it touches the bullet. Seat a few and inspect, adjust as necessary and you're good to go. After you make your final setting, check to see if a round will chamber in your gun.