Quote Originally Posted by fourXfour View Post
My bolt was not locking back when I shot 125 grain Gorilla ammo with the H2 buffer. It locked back fine with 125 grain Remington.

I tried the H buffer and could not get the bolt to lock back with Gorilla. I then tried a carbine buffer and it worked perfectly. I'm low on ammo and I will eventually try Fiocchi next.
Ran it with an "H" and "H2" buffer today with supersonic loads and the bolt locked back every-time. I'm pretty sure the added back-pressure from the Noveske KX5 helps a good bit as well.