Yeah, the free floating firing pin guns put a dent in the primer when chambering a round (AR15, M1 Garand, M1A and who knows how many others).
So?
I used Federal BR primers in my M1A for years.
I've never used anything but small rifle or magnum small rifle (bought 5,000 by mistake one time) in the AR15s.
Do the correct maintenance and lube on your rifle. Keep it clean.
If it makes you feel better to use harder primers, do it.
If it makes you feel better to carry a pistol with a firing pin block, do it.
If it makes you feel better to carry a certain brand of ammo/firearm, do it.
If it makes you feel better to believe what you read on the internet, that's fine, too.