Actually about any modern 45 Colt uses .451 to .452 bullets just like the 45 ACP. The .454 hasn't been used in years.

The ACP won't fire in your 45 Colt Contender though. About the only way to fire them in the same gun is by using different barrels (like the Contender can) or interchangable cylinders (like the Ruger Blackhawk).