Guys with different manufacturer built (or rebored, rebarreled) 338 Federals.
Is there any difference in the OAL of the round that will fit in the magazine?
I've had a Ruger and a Kimber 338 Fed. The Kimber is limited to ~2.82, while the Ruger mag allowed longer. I don't recall the exact limit, but I think I was loading ~2.84+.