where can I buy a .264 M1 barrel?

[jmoore]

unless you think they'll creep forward during firing and jam things up?

Just a SWAG but, yes. Misfeed, something, esp. as the case is so much shorter than 30-06.

[Bubba-7]

I have two M1s in 270, which does not seen that much different from 264. They do have less recoil and with a little more metal in the barrel, maybe a little more accurate. I purchased one new from Springfield Inc. (Special Order) about thirty years ago and I bought a 270 barrel from Gun Parts and had it put on a 9m/m barrel which was on a Blue Sky in the early 90's.
You know what a 9m/m barrel is? It is a barrel that will take a 9m/m round to the case at the muzzle.

[flying pig]

If you were going for accuracy what about 280AI? Lots of people seem to be using it for long range bolt action builds.

[browningautorifle]

a barrel that will take a 9m/m round to the case at the muzzle

Pretty funny...not very accurate. Guess it would be broadside at the muzzle...