Helped a fellow put a belemy spring in his encore a few weeks ago and he had a 264 win barrel on it,according to him it shot ok but nothing special,don't know if he was shooting factory or hand loads.
I just got a 25/06 to try on my encore muzzleloader and I am really surprized the way it has shot so far,at first I couldn't get it to shoot the 100gr and 117 gr bullets but it loved the 120 hornady HP every group I have shot with it so far has been less than 3/4 in and only have shot it one group @200 and it was less than an in.
Was at the range tuesday and another fellow I shoot with had some 100 gr sierra match bullets and let me try a 3-shot group with them and all 3 went in the same hole.
So with that I think the 264 would do great with some work or may with the first load tried.Would like to try one in a bull barrel just to see.
The fellow said he shot at the same range that I do but have never seen him there if I do<i will see if he will let me try his with the 264.