14 July 12
At an Urban Rifle Course in CO last week, one of my Instructors brought a Doublestar AR, which ran fine until the second day. Ammunition was WW White-Box.
During a live-fire drill, the rifle’s bolt-carrier stuck in its retracted position, within the buffer-tube. No amount of coaxing persuaded it to resume normal movement, so my Instructor, without hesitation, defaulted to his pistol and finished the exercise.
Subsequently, we were unable to get the rifle running in the field, despite the fact that we had several armorers among us. My Instructor switched to my DLS/CQB, which ran fine for the duration.
Yesterday, at Hi-Viz Headquarters here in Ft Collins, CO, my friends there discovered the issue: A blown primer had made its way (Heaven knows how!) into the underside of the charging handle, where it tightly wedged itself between the charging handle itself and the gas-key, promptly seizing the whole works!
I’ve seen many blown primers fall downward into the trigger-group, where they rarely cause a problem, but sometimes do, in spectacular fashion. I’ve also seen them jammed into the bolt locking-recesses, even into the gas-key spigot. But, this is the first time I’ve seen one migrate upward into the charging-handle area!
Doublestar in on my Recommended List, and still is. WW White-Box ammunition normally runs fine, and I recommend it too. My Instructor’s equipment was carefully selected and well maintained.
A blown primer is actually rare, probably occurring in fewer than one in 10k rounds. Military ammunition features “crimped-in” primers, which makes the event even rarer. But, no matter what brand of ammunition is used, and no matter how careful and conscientious we try to be, primers will occasionally blow out of cartridge bases, and occasionally lead to subsequent tactical issues, with any autoloading, military rifle.
And, until the day when we’re all shooting neutron-beam weapons, I doubt there is much more that can be done to reduce the frequency of this phenomenon.
The point is one which I stress regularly: Never carry a rifle without carrying a pistol also.
We drill transitioning from rifle to pistol regularly, just for the above reason.
Fail at your peril!