I know that when I go over 2100fps with either of the bullets I have used the most, the groups open up, just as yours seem to do. Above 2400fps the 210gn bullet is erratic. FWIW, 2400fps with a 210gn bullet in the .308 is right near max for jacketed at that weight.

Since my goal is MOA or under then I keep the speeds lower with the 1-10 twist.

Why was I pushing the velocity? I wanted to try for MOA at 600yd. I could almost get there at 500yd but the velocity is just barely supersonic. Past 500 they just kind 'scatter' :)

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