Gun is a converted to 45 ACP/Auto Rim Mark VI.Cylinders are .449-.450 bore is about .456.Bullets sized to .452 and were 12 BHN.4.0g of Clays @ 700 fps.Three consecutive six shot groups at 20 yards with wrist rest on sandbags.No leading and recovered bullets showed strong rifling with no apparent gas cutting.
George
click pic to enlarge and see data
(the 4.5g charge note was an error)