One thing I should have mentioned in this thread earlier . . . for break in, particularly the first ten shots, use a bullet with the longest bearing surface you can find. Even if the twist of the barrel won't stabilize it. I like the 70 grain Speer roundnose for .224, 160 Roundnose for .270, 175 Roundnose for 7MM, etc. And it really isn't necessary to load these break in rounds to full throttle, either. Roskoe