You bought a AO 1911 chambered in .45, that someone fitted a 400 cor-bon barrel in.
If the gun is reliable with .45 ammo, I'd say you got a good deal.
The 400 Cor-bon was Cor-bon's answer to the 10mm, or rather it was designed to mimic the ballistics of the 10mm. You have a .45 casing that was necked down to fit a .40 caliber bullet.
If the barrel was a drop in part, it would fit ...



