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Webleymkv · April 27, 2010, 02:35 PM

.38 S&W and .38 Short Colt are not interchangeable cartridges. The .38 Short Colt is actually the parent case for the .38 Long Colt, .38 Special, .357 Magnum, and .357 Maximum and thusly is smaller in diameter than the .38 S&W. While the .38 Short Colt did originally use the same .360-.361 bullet diameter as the .38 S&W, it used heel-based bullets while the S&W used the more modern inside-lubricated bullets. When loaded with inside-lubricated bullets, the .38 Short Colt will have a bullet diameter of .357-.358.

.38 S&W ammo probably would not even fit in a .38 Short Colt chamber due to it's larger case diameter. While .38 Short Colt ammo would probably fit in a .38 S&W chamber, it would almost certainly bulge or split the case if fired and most would consider such a practice to be unsafe.

As far as I know, Colt never produced the Police Positive in .38 Short Colt. Instead they were chambered in .38 Colt New Police. The .38 Colt New Police cartridge is nothing more than a .38 S&W loaded with flat-nosed rather than round-nosed bullets and the two cartridges are completely interchangeable. If you have a Police Positive chambered for .38 Colt New Police, it is perfectly safe and acceptable to fire .38 S&W ammo in it.

April 27, 2010, 02:35 PM	#2
Webleymkv Senior Member Join Date: July 20, 2005 Location: Indiana Posts: 10,446	.38 S&W and .38 Short Colt are not interchangeable cartridges. The .38 Short Colt is actually the parent case for the .38 Long Colt, .38 Special, .357 Magnum, and .357 Maximum and thusly is smaller in diameter than the .38 S&W. While the .38 Short Colt did originally use the same .360-.361 bullet diameter as the .38 S&W, it used heel-based bullets while the S&W used the more modern inside-lubricated bullets. When loaded with inside-lubricated bullets, the .38 Short Colt will have a bullet diameter of .357-.358. .38 S&W ammo probably would not even fit in a .38 Short Colt chamber due to it's larger case diameter. While .38 Short Colt ammo would probably fit in a .38 S&W chamber, it would almost certainly bulge or split the case if fired and most would consider such a practice to be unsafe. As far as I know, Colt never produced the Police Positive in .38 Short Colt. Instead they were chambered in .38 Colt New Police. The .38 Colt New Police cartridge is nothing more than a .38 S&W loaded with flat-nosed rather than round-nosed bullets and the two cartridges are completely interchangeable. If you have a Police Positive chambered for .38 Colt New Police, it is perfectly safe and acceptable to fire .38 S&W ammo in it.