Bought a 20" brx arp barrel on the equipment exchange here. Fire formed the brass with cream of wheat. Finally got it sighted in today. The mirage was horrible. I was surprised to fire anything that even resembled a group. I definitely need a new scope. I used 95 gr smk over varget powder. I'm thinking I'm gonna like this rifle. Fired one group. Then used the rest of the pressure checking rounds to adjust the scope. Measures about 7/16"