Re reloading ammunition for the Garand rifle, when I used one in competition, oal of 3.3- 3.4" worked fine using several different bullets (Sierra 180 & 168, Hornady 168 & 190, FA Match bullets, Sierra 165 grainers and such).
These were all jacketed bullets, none having a crimping groove. I never found it necessary to crimp, in any way at all, any jacketed bullet ammunition in any rifle that I ever fired.
I have seen a couple of bolt guns that would sometimes "pull" the bullet out of National Match 30-06 ammuntion. Suspect that the chambers of these rifles might have been just a mite short, combined with ammunition that was perhaps a mite long. Most often, one does NOT run into this sort of thing, however there is always the possibility of "tolerance interference", a polite term for what I above described.
Hope this helps.
[This message has been edited by alan (edited May 26, 2000).]