OK, let's see:
Epps -- will only do work in his shop, won't ship bbls, and his Imp's are too high pressure for No. 4's -- all of which I have by oral hearsay. Time to do some direct checking there.
.30-40...good idea that never crossed my mind. Will check with my local guy [Gary Cleland] on that one.
.405 Win...a sample cartridge sits on my bookshelf. Indeed, it is damn near a slip-fit, but the mag is too short, as you point out. A German gunsmith does all manner of No4conversions in a very classical style, and .405 is among them. So it seems that the mag alteration functions. Lost his site and was never able to resurrect it. His work certainly would fit in with this forum.
Simple is good, in this case, so Krag gets first investigation.
Thanks.
