I have a Savage 10 tact. 1:9 twist. The 52g Sierra HP are the starter for me, up to the 60gr bullets. I have had the rifle gone over, so I hope to attain the better accuracy, they claim, so far 1.5" is the best I can do at 100yd. That could be me, how ever my Parker-Hale 243 sporter will print .50 groups, at 100.