It was commercially loaded by Winchester, I don't know if it still is. The Grizzly is a modified 1911. I believe that Wildey chambered for it as well, and I played with an M1 carbine that had been modified for the round one time. I have a Ruger Blackhawk convertible 45 with one cylinder in 45 Win Mag. It's a fun round, pushes 300 gr bullets out handily. - dan