I've shot a 50 Alaskan with a short, ported barrel. It was fine to shoot off the bench, but it sure was loud. It was a Marlin 95 action modified by Wild West Guns.
If you've got a stockpile of 348 brass, you can reform and reap the benefits of greater case capacity than the Starline factory brass. It's a multi-step process to reform the 348 up to a straight 50, but Wilbe Lead knows a lot more about that than I do. Maybe he'll chime in on this thread.
The WWG modified Marlin that I shot was plenty accurate. Besides Marlin 95s, other good choices for modification would be the 1886 or 71 rifles, in that order. The 86 has the best feed system for reliable operation after modification. The others may take more work.
The 45 and 50 Alaskan rounds both offer enough power for pretty much any game on the planet. The 50 will throw big, heavy bullets fast enough to nip at the heels of some of the old Nitro rounds. With the proper bullets, it could be used as a stopping rifle, not just a hunting rifle.
The Hodgdon Annual Manual is one of the best sources for published reloading data for the 50.