Not quite a year ago I bought a RRA Predator Persuit which hasn't been out of the box yet. I think I'll begin shooting it in the spring but I'm starting to look into reloading for the rifle now. I have a set of Redding type "S" FL dies which I bought for my bolt rifle and picked up a box of Sierra 69gr HPBT bullets for the AR. My question is; can I just neck size tightly using a small neck bushing or is bullet crimping necessary in the AR's? If crimping is essential than what is the best way to accomplish this when using bullets that do NOT have a cannalure?