Were you running those 156s out of a PRC? I'm about to order a proof carbon prefit fora ruckus action and I plan on running primarily the berger 156s. I've read that the 4 groove rifling might be an issue but it's always with hornady projectiles and I'll only be running bergers.
I'm building a long range hunting rifle for my trips out to Wyoming. I have a ruckus XM, and I'm considering a proof research prefit. Does anyone have any experience with these barrels and 156 bergers?