I recently purchased a McGowen Barrel in .260 rem. 20" threaded muzzle from Gun Shack, Loves the 123 amax & 123 SST over 37g RL-15, shoots 1/2", I like my McGowen Barrel!!! Having said that it key holes the 130 burger's??? I have tried numerous different COAL with no success shoots the bergers 8" at 70 yards??? Any suggestions???????