WOW!!! I shoulda checked here first just to confirm that nobody cares about short actions anymore....
Well, yes....there is plans for a long action version BUT.....until the magazines are totally wrung out, field tested and approved, you won't see anything about it. That's why I kept this under wraps until I had it de-bugged and into production before I cut it loose, somehow I knew this would happen.
.223....not out of the question, but not bloody likely for a long time.

The Choate version will fit either stock, US or UV. I can inlet the Medalist, that's a given, but the only thing I don't know for sure is the depth of the stock in that area and it might be thicker, leaving the frame below the the wood line. Not that it would be a problem, just maybe unsightly, but I'll bet it's pretty close.

The whole idea behind this was to make most of the applications "drop in" fits. Even for a stagger feed, one could use a stock originally for a centerfeed DBM and simply slot the front hole, or remove the pillar. The Choate Tactical stock is a good example: although it is for a new centerfeed DBM, the front hole that is through the aluminum chassis can be slotted back, and now it will fit a stagger feed. The B&C are the same way with the aluminum chassis, you could go either way.
The DBM inlets will vary slightly from different manufactures, so it may be neccesary to tweak things with a dremel.
"J" series.....OK, Frank....yer pushin' it now. It would be possible, but that would be a total custom application.

As to who is making the magazines...I am not at liberty to discuss that at this time, but I will say that they are used on alot of high-dollar custom tactical rigs.