An Olympic Arms Registered Receiver KABOOM WOW!!!

[Quarterbore]

Following is a series of photos and story that is being reprinted here (with permission) until I can add it to the main site at Quarterbore.com. You can see the original thread here:

http://ar15.com/forums/topic.html?b=3&f=14&t=238612
Posted by: rgrrick 6/1/2005 1:24:59 PM EDT

On May 30, my birthday, myself and my brothers and my friend RGRchristian (from the net, Subguns.com,Sturmgewehr.com) went shooting at our private spot with our M-16s and a few other class III items we were there all day trying out my new beta mag and just blasting. It was the end of the day and we were almost out of ammo and did a few beta dumps out of different uppers with video camera running, to catch the fire balls. I switched out my 11.5 upper to my M4 flattop upper with about 15-20 rds left and said don’t bother to tape only a few rds left, I pulled the trigger at about round 5 my gun made a very different bang more like a concussion sound and I cant understand why Christian is yelling at me are you all right are you hurt and pushing on my chest and looking at his hands for blood (Ranger training kicked back in). I said no I am fine what happened?

Than I looked down and saw the mess HOLY SHIT what just happened?? My upper receiver is only half here the bolt carrier is only half here the beta mag is on the ground the mag catch is gone the bolt release is broken in half. The only injury I received was being hit by the mag catch or the bolt release on my left bicep it looks like I was hit from a paintball gun. After everyone calmed down we started looking for the parts we found the half of the upper about 35 feet from where I was standing we could not find the mag lips from the feed tower on the beta.

Here are the gun details lower is a Paws/Olympic the upper and all parts were Olympic,2 pcs 9mm buffer, standard power buffer spring, Beta C-mag, Arms #40 BUIS. When we got back to my house we inspected the gun to find out what happened, Christian and I had been to armors school, we determined that the gun fired out of battery or slam fired because the barrel extension lugs showed that each lug was engaged less then 25% (it looked like a grinder was put on each lug only up to 25%-35% at the beginning where the bolt first engages the extension) so the case was not fully supported and the bolt not fully locked up and boom.

You have to see the pictures. I credit not being hurt to the strength of the upper and bolt/carrier for holding together as much as it did, what saved me from having a few more scares on my pretty mug the most would have to be the ARMS #40 BUIS it kept the upper together way longer then I would have expected it to do, the cross bolt bent and stretched until it could not hold anymore and caused the receiver to get launched up and to the right of my head/face. The only damage to my lower besides the mag catch, bolt release is the mag well got bulged out a little bit, I was going to send it to Olympic for replacement because it is a little out of spec now I have a real reason to.

I am so glad I got a Paws/Olympic for this reason because this can happen at anytime to anyone. And yes it was factory ammo Remington 55gr FMJ.

[Tweak]

classic overpressure blow

[Carpe Diem]

Hmmm, overpressure with factory ammo? Looks far more like an out-of-battery discharge with high pressure gas vented into the action. I'd expect more barrel/extension damage (sheared lugs, etc.) from over-pressure, but that's not in the description. Based on the text above it was an out-of-battery discharge - but then again, who knows what really happened?