Quote Originally Posted by cysoto View Post
I have only seen it tested with 142 grainers and it was piercing primers left and right.
Sure it was not the 6.5 Creedmore? Those are higher pressure and can have primer problems. That or a just loads that were too hot!

I ran hundreds of pretty stout 142s through my AR-10 .260 with no pressure signs at all. For accuracy reasons, I dropped back to the 123s in the gas gun.