Blown Primer during range day

KMo1205

Member
So I went to the range today to do some tests with new ammo. I was comparing Remington Fusion 62gr., Freedom Munitions 62 gr. PSP, M855, and M193. Half way through the test my trigger locked up. The bolt chambered the next round but my trigger would not reset. After a couple of minutes, I discovered the two pieces of a primer had wedged itself under my trigger, preventing reset.

I'm assuming the cause is an over charged Freedom Munitions 62 gr. PSP (I found the casing to confirm) and the solution is buy more reliable ammo. There was no noticable difference in the shot, as I didn't discover it until a few rounds later.

Anyone else have this happen to them during training? Ideas to clear or properly diagnosis in the future? Could my carbine equipment be a factor? (BCM 14.5" mid, 1/7, BCM BCG, carbine buffer, ALG ACT trigger)

In any case, I'm glad it happened at the range as it was a great learning experience on malfunctions.

image.jpg
 

Boone

Newbie
There are those who have dug a primer out from under their trigger, and those who will.
I wouldn't stress about blowing a primer out of a 5.56 case. It could be a result of a higher pressure/slight over charge, or a loose primer pocket on mass produced ammunition. Being that Freedom Munitions is re-manufactured ammo they could have swag/reamed the primer pocket to large creating the loose primer pocket. I have heard several complaints about Freedom Munitions popping primers, generally if you contact them they will replace the lot of ammunition you purchased.

In any case your equipment shouldn't be a factor here.

*Edit to add* I don't see the tell tale smiley face swipe on your brass that's normally associated with high pressure. I'd say loose primer pocket.
 

556223

Newbie
It would appear to me that this is an over-pressure problem based solely on the single photo (nice photo). The case head shows a brass "sprue", next to the A in USA, which indicates that there was so much pressure that some of the case head brass was forced/squeezed into the ejector hole. I would assume that you did not find a "sprue" like this on any of the other manufacturers' empties. The photo also appears to show that the primer was crimped into place properly but the excessive pressure force the primer out, leaving the sharp edge of the crimp visible. If you were popping primers from several brands of tested ammo then I would suspect your chamber might not be a true 5.56 chamber, but with the obvious "sprue" on the case head this screams "Way over-pressure" to me.
 
Top