I just finished my first build with a Mcgowen semi custom barrel. The barrel is a 28" 8 twist contoured to pacnor#7 chambered in 7mm Remington mag.I started load development today and I'm very impressived I not was able to get time to shoot two loads they both shot about the same .410" and .430" four shot groups at 100yds off bipod and a bag.I'm very happy so far barrel looks great and shoots great too the only issue I have is when I clean it I have to rip a cleaning patch in half to get it to go in the barrel on a 7mm jag if I re a full one I can't get it to any further than just outside the bore guide. Am I doing something wrong?