The Firing Line Forums - View Single Post - .223 :crimp on bullets with no cannelure and a case capacity question?

alan · April 20, 2000, 06:27 PM

Gopher:

Iam not terribly familiar with the .223, but using jacketed bullets, do you really need to crimp in the first place. When I shot high power rifle in competition, using a Garand, I never used any sort of crimp with jacketed bullets.

As for the bullets with a crimping groove, I assume you were roll crimping, without the groove, you could taper crimp, just enough so that bullets did not SET BACK into the case, when feeding. You are using a self loading rifle, I take it.

As to cartridge cases, there can be significant differences in case volume, which usually would show up via weight differences. Thick walled cases are heavier. Usually, military brass will run heaviest, Winchester commercial brass will be lightest, Remington somewhere in between. The other brass you mentioned does not ring a bell with my memory, such as it is these days.

In any event, since the same charge, stands much higher, sounds like a large volume difference. I would back off on charge weights, perhaps 10%,, then work back up. Compression of powder does not necessarily hurt anything, but that would depend on what powder, what caliber and how much compression. With 7.62mm NATO Match ammunition loaded at Lake City, a few rounds that I pulled down contained about 41.5 grains of what looked like 4895, and it was a compressed load. It shot, in bolt rifles, without problems.

April 20, 2000, 06:27 PM	#3
alan Senior Member Join Date: June 7, 1999 Posts: 3,847	Gopher: Iam not terribly familiar with the .223, but using jacketed bullets, do you really need to crimp in the first place. When I shot high power rifle in competition, using a Garand, I never used any sort of crimp with jacketed bullets. As for the bullets with a crimping groove, I assume you were roll crimping, without the groove, you could taper crimp, just enough so that bullets did not SET BACK into the case, when feeding. You are using a self loading rifle, I take it. As to cartridge cases, there can be significant differences in case volume, which usually would show up via weight differences. Thick walled cases are heavier. Usually, military brass will run heaviest, Winchester commercial brass will be lightest, Remington somewhere in between. The other brass you mentioned does not ring a bell with my memory, such as it is these days. In any event, since the same charge, stands much higher, sounds like a large volume difference. I would back off on charge weights, perhaps 10%,, then work back up. Compression of powder does not necessarily hurt anything, but that would depend on what powder, what caliber and how much compression. With 7.62mm NATO Match ammunition loaded at Lake City, a few rounds that I pulled down contained about 41.5 grains of what looked like 4895, and it was a compressed load. It shot, in bolt rifles, without problems.