I was actually thinking the 410 version, if I am correct that the bolt lugs and trunion of the 410 are actually as strong as the 7.62x39mm version. The 410 version would be much better for feeding the rimmed round, and could prabably even use the same 4rd magazine.
I inspected a 410 at the gun show and it sure looked like it had the same lugs as the 7.62x39 and 223, and trunion, though the bolt head went into the barrel as necessary for reliable feeding.
I'm only in the feasibility determination stage, trying to figure out if it would actually work. One of my reasons for waiting is that I'd want to know if and what it would take to use in Canada, since that's where I'd have the most use for it. I live in PA where we can't use semi-autos for hunting, so I wouldn't really have any use for it here.
If the 444 Marlin is too high powered but not by much, I might consider 44 Rem Mag with less grand hunting plans.