I am interested in working up a 338 win mag and have both a 264 win mag and a 270 weatherby mag as potential donors.

I believe the 270 WM has a case length of 2.545" whereas the 338 is about 2.5". It would seem this would not require significant alteration, but the 264 win mag donor is pretty much a a 'drop-in'. I'm just not as certain that I want to re-purpose the 264.

My question is how much more 'smithing will the 270 WM require than the 264 to become a 338, considering both the action and the box?

No mod needed I say.

OP,
It might be a great topic to share in the gunsmithing section since there are lots of knowledgeable guys who frequent that section too.

I'd have to agree with dpcd, no mods needed with either one.

Zeke

You are right. I should have posted in the 'smith section

thnx

All you have to do is rebarrel the gun on either. The bolt face is correct and you may or may not need to tweek the action in the 270 Wby., make a dummy case and see if the .338s feed in both. Im sure they will in the .264 but the 270 WBy may need some tweeking??