I recently got a new "name" cut rifled barrel put on my FN mauser rifle by a top flight benchrest gunsmith.Visually the barrel and chambering look supurb. Before with the factory barrel it was a 1-1.5 MOA rifle. I've shot it and with the exact same rest/loads/mounts/scope/shooter its now a 3" for three shots rifle at 100 yards. Caliber is 30/06. Original barrel was 1-10 twist 22" ...new one is 1-11 twist 25". Load was light bullets 135-125 with moderate loads of powder, Varget, H4895. The rifle had always been a very accurate rifle so I doubt is the bedding or or mounts/scope. Action has always been glass bedded and the barrel free floated. I noticed the fired cases were sooty all the way back to the rim. All along the case. So the brass isn't sealing. Could this be the trouble? What would cause this? Its never happend before. Load was 45 grains of H 4895 behind a 125 nosler BT and 47 grains of Varget behind a Berger 135. Both loads were right at moa and the Noslers would shoot 3 into 3/4 inch at 100 with the older barrel. I'm going to try heavier bullets in it but I wanted to shoot the lighter weights. Any advice on what to try to get the groups under 2 inches at 100? Differnt primer? Bullets seated just off the lands. No pressure signs. No primer sticking out. Fired primer is flush with case head. Just puzzled at this. Thanks! FNMauser