I have an RRA NM, and a couple of other AR's. While I demand top accuracy, I still feel that if I'm going to own a military weapon, then it needs to operate like a military weapon.
Therefore I load all my cartridges to a max length of 2.260" so they fit in the magazine. As others might load their cartridges longer so the bullets are seated closer to the lands, (and they hand feed their load into the chamber), I do not. I believe this has hampered my attempts to get the best accuracy that a handloader ordinarilly should be able to attain.
As far as excess pressure, as long as you don't go to extremes, I have seen some very flattened primers on military loads, so you should be Ok. With higher pressure loads over extended periods of time, I was warned that I might end up replacing the bolt, but the rifle itself doesn't actually bear the grunt of the pounding and "loosen" up.