as far as the sagia feeding shot gun shells the 410 has a bullet guide/shroud above the the barrel that is part of the barrel. you really cant do that with a AK bolt.
with the chamber you will need the free bore in front of the bullet to have the aproperite angle at it transitons into the rifleing this is important to avoid high pressure.
you will have to or should cut the throat as well as the neck of the chamber with a piloted reamer. these are not super expensive although I have not looked at .50 stuff. dont forget theat the 50 beowulf headspaces off of the rim so there needs to be a sharp non taperd rim for the case to seat against. then a slightly smaller area for free bore. I would call a few places for a reamer befroe trying to make one. the time and money not to mention the chance of wreaking a already short barrel is not worth it IMOO. I f you do make a reamer more power to you.