I have a 28" 1:8 twist PacNor barrel in a 22-250AI use for a coyote gun. It works really well with the 75 AMax, 77 and 80 SMKs. However, running a 69 SMK at 3600 fps works really well to. Once I got my first 6BR, I took the barrel off and haven't had it back on in +3 years. I want to ask...