So I just bought an ar-50, and I Would like to mount it to an A-frame I already have. Does anyone know what kind of T-slot is machined in the bottom? Is it an Anschultz rail? A Freeland rail? Any standard machinist t- slot? Or is it something proprietary?? I have seen rail adapters but they all mount a rail or a sling swivel, I want to mount the rail flush to a plate so I just need the T-Nut that goies inside the rail! HELP!!!!