CCI Blazer/Open-Bolt Warning (8/21/02)

 
Topic: Aluminum case Blazer ammunition fired in an open bolt gun.

Warning--Don’t fire CCI Blazer ammunition in open-bolt firearms.

Rick Wyant was recently firing one of our laboratory’s 45 ACP MAC-10 machine gun that fires from an open bolt when he began to experience fired cartridge case jamming, as well as a stuck FMJ bullet in the barrel of the MAC-10.  An examination of the fired cartridge cases revealed that they had blown case walls.  

We surmised that unlike ammunition that is fully supported by the chamber before it is fired, that the round was being detonated before it fully entered the chamber of the barrel.   Brass cartridge cases did not have this problem fired in the same gun, but the aluminum casings do not have the same metallurgical properties.

It should be pointed out that this is not a problem of faulty ammunition, rather subjecting the ammunition to a situation that it was not designed for.

Evan Thompson
Rick Wyant
Washington State Patrol