Serial # 335150-C The collet bushing was introduced by Colt in 1970 and is easily identified by being made of spring steel with four "fingers" at the rear. The last batch of standard commercial Governments in 1970 incorporated the new barrel bushing and matching barrel (which has a slightly belled muzzle) as a test run. These pistols (approximately 1500 made) have conventional post-war commercial markings, and have a special "BB" marking underneath the serial number. The slides on these models have the Pre-Series 70 factory stamps. This example has a blued finish, checkered walnut grips, gold medallions, 5" barrel, and is chambered for the .45 ACP. The barrel is stamped "Colt .45 Auto BB" as visible through ejection port. The gun remains in virtually as new condition. There is no idiot line visible and has just a couple of extremely minor storage marks on slide. Mint bore and action. Comes in an original Colt two piece box which is numbered to the gun on bottom. No paperwork.