I've had 2 264's. The first one I had, would blow primers with factory loads, yet a bullet would fall into a case and the case came out at spec., so tight necks weren't the reason. The bullets were not jamming the throat, either. It was the weirdest thing. The bore and groove diameter was also 'right'. I could not figure it out. I had to go to IMR4895 powder due to the capacity reduction necessary to get it to stop producing excessive pressure. I became concerned about the 'reduced loads of 4831 the rifle. was making me use.

The second rifle, a post M70A Winchester shot well, but with it's 22" bl. gave poor speeds at max loadings. I re-barreled it to a .458 Alaskan then sold it when it finished destroying my shoulder cartilage.

The .264 was an interesting round, but I think the 6.5/.284 is a superior round for all round use, as in target or a long range deer/goat/sheep rifle quite capable of taking elk and moose as well.