So here's the finished gun with ammo. The cartridges are made from .303 British cut to 1-11/16" then resized to accept the .452 heel-base bullet. Loaded on top of 10 gr. of Trail Boss with a large pistol primer. These loads sound supersonic to my ear, but that's just a guess since I don't have a chronograph. Recoil isn't bad; the 3-1/2lb. gun soaks up a lot of it. Muzzle blast is loud, but the muzzle-flash is smaller than you might expect.
Yes, I mean to load the Holy Black, but that has to wait for outdoor shooting weather; indoor ranges don't like it when you lay down a smokescreen. I also want to photograph the BP muzzle-blast in low light- it should be
EPIC! Now I need to mount a front sight and see how it groups.