calib

Do you load your oun??
If you do 1+ on 82boy's post if you do not, you are wasting your time with the 243 AI and a 8 tw, you will not see any advantage over a standard 243 with either an 8 or 10 tw.
If you do load there are other options than a 243; 6BR, 6XC, 6 X 47 Lapua and others and they will get longer barrel life.

22 Mag