Re: Ruger American 22-250
Great! I am interested in one of these for a beater rifle. Can't wait to see how it shoots. Of particular interest is how it performs with heavier bullets. The 10 twist should be good for at least 69 grain bullets. I have run the numbers that I could find through a stability calculator and it looks like 75g BTHP's should work. The 75g AMAX's are right on the edge, according to the calculator I used.
At any rate, Hodgdon says a 22-250 will do just about 3500 from a 24" barrel using Superformance powder and 70g bullets. Maybe 3400 from a 22" barrel? I am thinking 3400 with 69g SMK's would be a pretty mean long range varmint/yote load.
I am looking forward to your range report!