I decided to put together this post after two recent incidents on the range. In one, a customer loaded .380 ACP rounds into his 9mm pistol and while they fed, chambered, and fired properly, they didn’t cycle the action.
In the other, a different customer was having a problem with his new AR pistol. The bolt wouldn’t go all the way forward when he chambered a round, and that was because he was trying to load .223 Remington rounds in a gun chambered for .300 Blackout.
Those two incidents were resolved without injury or damage to the firearms. Sadly, this isn’t always the case. Most of the time, a firearm will only chamber and fire the correct cartridge, but the exceptions to this rule can be disastrous.
With certain bullets, a .300 BLK round will chamber in a .223 Rem or 5.56mm rifle because the case head is identical and the case is shorter than the .223/5.56. In most rifles, the extractor will keep the base of the cartridge against the bolt face and the firing pin will set off the primer. The shooter is then presented with a .30 caliber bullet trying to make its way through a .223 caliber bore. The best case in this situation is damage to the gun from the pressure spike; the worst case is injury or death to the shooter and anyone else nearby.
I can’t stress enough the importance of making sure that
correct ammunition is used in a gun. However,
even if it’s the right caliber, it may still be too "hot" for the firearm, which can occur when shooting +P
or +P+ ammunition in guns not rated for that energy level. It breaks my heart
when I hear about a vintage revolver being blown up because someone fired a
cartridge that develops far more pressure than the gun was designed to handle.
For example, many British Webley revolvers originally chambered in .455 were cut for .45 ACP in moon clips when they hit the surplus market after both world wars. The .45 ACP round will chamber and fire, but the pressure level of 21st century .45 ACP is considerably greater than 20th century .455 Webley. Owners of these revolvers should either handload low pressure rounds or relegate their Webley to "safe queen" status.
Less dangerous, but not entirely without risk, are surplus revolvers originally chambered in .38 Smith & Wesson which have been cut for .38 Special. The .38 S&W cartridge is both slightly wider and slightly shorter than .38 SPL, and importers would cut the chambers in the cylinder deep enough for .38 SPL to fit and call it a day. Firing .38 SPL out of these revolvers almost always results in ruptured cases and can cause erosion pits in the cylinder walls, both weakening the cylinder and making extraction more difficult.
Something similar was done to .38 SPL revolvers after the introduction of .357 Magnum, since the .357 MAG case is dimensionally identical to .38 SPL other than being 1/10th of an inch longer. Some people would have the chambers deepened in their .38 SPL revolvers so they could chamber .357 MAG cartridges, perhaps because they didn’t want to buy a new gun. Needless to say, this rarely ended well for the revolver.
I will list more examples in a future article, but I hope by this point the message is clear: know your firearm and its appropriate ammunition. A good resource is SAAMI, the Sporting Arms and Ammunition Manufacturers Institute.
Be careful, be safe, and enjoy many more years of shooting without blowing up any guns.
Be careful, be safe, and enjoy many more years of shooting without blowing up any guns.
No comments:
Post a Comment