to crimp of not to crimp
1) 30.06 bolt action (do you crimp at all...I cant remember)
2) 44 mag semi-auto
3) 38\357 revolver
4) 45 Semi-auto (If all goes well I will have one by xmas)
1. In magazine fed bolt guns, with jacketed bullets, I never crimped. I also competed with an old M-1 rifle (gas operatded) years ago. Never crimped with that either.
2. With lead bullets, probably taper crimp a bit, to keep bullets from moving back into the case, during feeding. You could roll crimp, assuming there is a crimp groove in the bullet. With jacketed bullets, possibly taper crimp. No roll crimp unless the bullets have a canelure.
3. With 38 Special, and cast bullets, I taper crimp. With roll crimp, case length is more critical, in any caliber, than with taper crimp. I sort cases by length, and adjust dies accordingly. Do not overcrimp in any caliber.
4. Taper crimp only, with cast bullets. Taper crimp with jacketed bullets, do not overdo the crimp.