I picked this up today at a tiny gun shop in Woodland Park Colorado. We also got an AK47 with laminated stock.
Its the Prairie River Arms - Bull Pup in .50cal.
I checked at the store and yeeeep! It was loaded. Got home and pulled the nipple, found goex 2f in there and possibly a round ball? Fired it off and it didn't kick at all. Trigger is maybe 1/2lb "Measured with scale and it breaks at 11oz!!" You sneeze and it will go off.
Cleaned it tonight and checked the bore, PERFECT! This gun looks as if it was loaded and then forgotten about. No marks whatsoever in the bore or even at the crown. Whoever shot it, shot it very little. The rifling looks amazing and crisp. Very narrow lands with wide grooves and maybe .010" deep rifling.
Stock is walnut and a thumb hole design which feels awesome when you shoulder it. Has a few dents and scratches but once i finish the Apollo i will start on this stock. Gorgeous muzzy and one heck of a find!
Did the measuring trick and came up with a 1:45 twist, so its most likely a 1:48 deep groove twist. Round balls and conical should do awesome in it.
I also found that you can use AR15 - M16 style front sight and the entire rear sight piece on this rifle. I'd have to drill and tap a hole for the front mount however.