New here, I don't know if this is the right forum. After a ton of reading I am puzzled why my velocities aren't higher. I had a new 26" shilen barrel installed a while back. I have tried imr4831, rotumbo, RL22, RL25, all as high as 1gr above max. None can move a 162SST above 2800fps. The chamber was cut wrong and has like .100" freebore. I have de-fouled the barrel several times trying to get different results. I was going to toss the barrel and buy a new one when my new gun smith suggested cutting the barrel back .200" and rechamber. I don't want to invest in a barrel I don't have confidence in and low velocities. The old 24" barrel used to shoot 160 game kings 3050fps and 1.5" group at 200 yrds. The shilen can't make a 4" group at 100 yrds, at less than 2800fps. Should I rechamber, or follow my gut and buy a lilja?