What twist rate is best for 75 grain bullets in a .22-250 at 3100-3200 fps. What kind of life will I get from a barrel with these types of loads?

I would think 1 in 9" would do the trick. Savage makes some of their .224s with this twist. I imagine others do as well, but don't know for certain. Best wishes.

Cal - Montreal

If you mean the 75 gr AMax my .224" magnum wildcat twisted 1-9" would not stabilize that bullet nor the 80 gr Sierra. I would order a 1-8" twist if I still wanted such a .224".

It's a lot easier to just shoot a 6mm with similar weight bullets but what the heck.

Hello,
I shot a Krieger barreled Rem. 700 in 22-250 for quite a few years and the twist was 1/8 for the SMK 80's and it worked fine on out to the 1000 yard mark. Also had a Douglas barreled one that shot outstanding as well, so the combo works. Will say that in my case, I could obtain veloicity over 3000fps, (had 30"barrels) but best accuracy usually occured around the 3000 mark, not on up there in the 32-3300 range?? Probably some stability issue, but it worked very well.
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dsiteman