I am new here, so first off hello. A few months ago I got a newly made .338 win mag from a gunsmith friend of mine. It has a Einfield action with different Mauser parts tossed in for good measure, it is glass bedded, and free floated with a muzzle break. 21" barrel 24 with the muzzle break. I am having a hard time getting it to shoot under 3" groups at 100 yards. Strangely it shoots better at 200 and 300 yards. I am loading the brass with H4350 Remington 9 1/2 M primers and hornady 225 grain SST. At all powder loads I get the exact same results. Dose anyone have any suggestions as to what I should try next? The scope is an old redfield 3x9 it dosent seem to be moving around in the mounts. Not bragging just saying this because I know it will come up. I shoot sub MOA with all of my rifles except this one.