I have a Colt Combat Commander in 9mm Luger, but the barrel is marked ".30 Luger." Apparently they had leftover barrels from a foreign (Italian?) order and just rebored and re-rifled them. I wrote Colt for info and they told me I could send the gun back and they would replace the barrel for the proper caliber!
Actually, I would like to get a 7.65 Luger barrel for that gun, but Colt disavows all knowledge of such a caliber.
(As an aside, the 7.65 Luger or 7.65x21 is sometimes confused with the 7.65 Browning, which is the .32 ACP and an entirely different cartridge.)