Hunting Forum

I hesitate to respond to your question Joe because I have my preferences, they may not agree with others, and I am not looking for a fight. For the rifle cartridges that I reload, it is a mixed bag as to whether I taper crimp or not. IMO most bottleneck cases do not require crimping. The tension of the case mouth holds the bullet properly in place without crimping the mouth of the case into the bullet. Bullet crimping works the mouth of the case excessively, and shortens case life. It also requires a bullet with a cannelure into which the case mouth is crimped. I do have reload two cartridges for which I crimp into the cannelure of the bullets. I crimp the 30-06 ammo I load for my M1 and I crimp for my .338 Win Mag. I do not crimp (and set the dies so they do not crimp) for my .222, 22-250, .243's, and .270. I crimp for the 30-06 because I want the action to cycle the same every time, so I try to make sure that they pressure built up to overcome the static friction of the bullet to the case is the same every time. (That is why I do it, it may be so far in the bug dust that it is a waste of time, but true or not, that is what I do). I crimp the .338 Win Mag because it kicks like a mule (I hate recoil) and I do not want the seating depth of the bullets to change for those in the magazine.

For the rest, I do not think they kick hard enough to impact seating depth.

Probably does not help you, but above is my reasoning for, crimp or not to crimp, for the rifle cartridges for which I reload.

jack

Joe you should be crimping for the 35 Rem that is used in a Marlin. The shells in the tube magazine are under spring pressure, if the bullets are not crimped, the combination of recoil and spring pressure can cause the bullets to move back into the case. This may cause the pressure to rise and or cause feeding issues.

If the Barnes bullet data says crimp, then I would crimp. I do not see any reason to crimp 'regular' bullets (like a Sierra Gameking) in your 300.

Your reloading manuals (you do have at least 2 don't you?) should have good information on crimping. Try rereading those sections and see if that helps you to understand.

Dale

I think there has been some confusion creeping in here. A Roll crimp is what most standard dies produce if adjusted down far enough. It is required for revolver, very hard kicking (think 458) and tubular magazine ammo and is optional on most rifle ammo. A taper crimp is used on cartridges that headspace on the case mouth, e.g. 380,45ACP,9x19,40S&W, 357Sig. The Lee "Factory crimp die" uses a collet to symmetrically press the last portion of the case into a cannelure - it is unique to Lee. Generally lead and plated bullets can be crimped even without a cannelure , as can some pure copper jacketed bullets (Hawk or Original Barnes), if you are careful. Monolithic bullets (GMX, Barnes TS, etc) and conventionally jacketed (gilding metal) bullets require a cannelure. Most bullets have the cannelure already positioned for standard chambers - e.g. Joe T's 35 Remington. If you need a non-standard cannelure position, you can get a cannelure tool from C-H tools and perhaps others.