The only cartridge I crimp is for my Winchester 30-30 because of the feed mechanism and tube magazine. I do not crimp any other cartridge and have never seen a need to in 45 years of reloading with the exception of my 30-30 and the pressure exerted on the bullet tip when loading.

In the last two years I have acquired a M1 Grand and two AR 15 rifles and I do not crimp any of the loads for these rifles and I have not as yet seen any bullet slippage or movement. BUT these rounds are not carried for hunting for long periods and unloaded many times. Meaning I have looked at a few of the remaining rounds in these auto-loaders and checked for movement a few times and seen nothing wrong.

If you can push on a loaded round forcefully placing the tip of the bullet on your reloading bench and pushing hard on the base of the case and see no movement your good to go.