Its a certer feed magazine system and it holds three on the mag. They are pretty easy to get most of the time but currnetly HS is trying to find another casting company to make their floorplates. Seems the one they were using went out of business.
There needs to be some slight modifications on the stock to accept this system but I have yet to find one that would not allow it.
The center feed design is dramatically better for a min taper, sharp shouldered case design. Plus the same system works great for my even fatter 277 and 7mm AMs as well.
They are not cheap though, about $230 currently for the floorplate and one magazine.
Allen Precision Shooting
Home of the Allen Magnum, Allen Xpress and Allen Tactical Wildcats and the Painkiller Muzzle brakes.
Hey Kirby, just thinking out loud here; but have you thought about mounting the barreled action in a barrel bedding block in a sacraficial stock just to compare accuracy potential. That is one thing I have never seen or heard an actual range test comparison of. Identical barrel, identical load, accuracy differance by thearetically shortening the length the barrel has to whip. I was reading an artical the other day on heavy guns and how no matter what, if you make the gun so heavy to eliminate recoil it will still jump and produce worse groups. But that was about guns over like 80-100 pounds. Anyways I would be interested in blocked gun info if you ever run across any. One day Id like to build a heavy gun and it will probably end up like yours, I love the lines without the barrel block.