We were running drills today, one of my students transitioned to his handgun, and finished the drills running his pistol. Once I called the line cold, he called me over to him.
The bolt was stuck fully to the rear, in the open position. Charging handle was inoperable… Chamber clear, no bolt over brass, etc.
Bottom line, I could not for the life of me, see what the issue was. In the end, had to disassemble the rifle. Got out my tool kit, took off the stock, castle nut, removed the buffer tube, being careful since the buffer spring was compressed.
Once I got the buffer tube assembly off the rifle, I pushed the bolt forward and felt resistance. Looking all over the place with my pen light… I found the culprit.
Primer unseated out of the cartridge, and lodged between the bolt and the upper receiver. Very interesting stoppage… made the MIGHTY COLT stop in it’s tracks.
I don’t know if this is the proper forum for this post, if not… my apologies. I just wanted to share this stoppage.
I have encountered blown primers falling into the fire control group, but never wedging up between the BCG and the Upper Receiver.
Also, the operator was running iron sights for this drill.
Intriguing. Thanks for sharing and the pics.
Would any sort of remedial action have cleared this or was it stuck so stiff that only your disassembly could free the BCG? What brand/type of ammunition was being used? Reloads?
The chamber pressure of this round is so high that it is right on the edge of doing this sort of thing on a regular basis. The higher environmental temps of Iraq are a contributing factor. This environmental temperature influence on the pressure of the round has been known to hunters in equatorial Africa for many years. We have sacrificed a significant degree of reliability to gain another 50 meters of effective range. If I were king, I would order the chamber pressure of 5.56 to be reduced by 10%.
Un-crimped primers and reloaded ammo are the worst offenders. Use only crimped primer factory ammo for critical situations.
This is an agency rifle, and the operator was using old M193 (SS109) 5.56 ammo. The cartridge case was stamped for Lake City, and according to the operator, was old training ammo that they brought to “burn up”. This ammo was causing several hung cases in the chambers… and was giving light primer strikes on several of the other rifles. It was good, because those running it, were really getting their remedial action drills down pat.
The stoppage had the BCG locked up so tight, the only way to free it was to remove the buffer tube assembly.
Since the M193 was old training stock, do you think they might’ve stored it in too hot a location at some point? If so, that could lead to powder degradation and pressure spikes which might explain the hung cases and the popped primer.
We had a huge lot of Federal uncrimped primers create havoc. Many pallets went back.
Most of the issues were in the FCG where 2 rifles went auto. However I have seen blown primers end up in the lug area and one rifle locked up tighter than a drum from a primer wedged in the cam pin cut out on the carrier.
Popped primers are more common than most people think. Popped primers landing in the most weird places (Cam pin holes, inside gas keys, in gas tubes) and locking up the weapon. If you’re lucky, it will just pop loose and not get lodged into anything. As others have stated, it’s usually with out of specked chambers (BM, Oly, Stag, DPMS) and XM193.
I have heard about this but never seen one. Almost all of my shooting has been military rifles/carbines and ammo (M193/M855). Is there a known way to clear this type stoppage without disassembly?
SS109 is the actual 62gr bullet with the steel penertator. US ammo loaded with this bullet is M855. If this ammo was real M193 there is no telling why it was sold off, and what issues that particular lot of ammo might have had.
The ammo was training rounds that the department brought to the range with them to use during the class. Where they bought it from, I have no clue. I did not ask.
How the agency stored it is also unknown to me. I dealt with the stoppage, and wanted to show it since it’s the first time I had ever seen it.
We had a few students that bought some reloads with them… 55 grain… that they purchased on their own, because their agency did not provide them with ammo for the course. They had issues with the cartridges getting stuck in the chambers… but this blown primer was from the M193.
The civilian variants of M193, start with an X, since it is illegal to sell real M193 to civilians. I honestly don’t think they make real M193 anymore these days. The XM193 variants (XM193C,D, F, etc…) seems to be the main culprit in most anecdotal stories, but it has happened with other brands as well, again with manufactures to the far left of the chart, with barrels stamped 5.56, when the chambers are in fact .223 chambers. In a VTAC 1.5 Carbine class, one guy (don’t remember the weapon) had so many popped primers with XM193 ammo, he couldn’t make it through a single relay without getting one on TD 1. Talk about frustration and being pissed off. Lucky he was able to obtain another case of ammo of a different type to finish the last two days.
Unfortunately, if the primer get’s stuck in a weird location where it locks up the gun, you will have to disassemble the weapon, remove it and inspect for damage, or you should, before operating the gun again safely.
This M193 does not have a green tip. I was incorrect in calling it SS109 I guess. The boxes are marked M193, and the rounds do not have a green tip. I do not recall the boxes having an “x” in front either. This ammo belonged to a Federal Agency, so it was not civilian.
Since it sounds like you were able to push the BC forward by hand, do you think it could have been dislodged by bumping the muzzle on the ground or a hard surface?
I’m thinking about possible emergency action here.
Honestly… I could not make the BCG budge until I relieved the pressure off the buffer spring, by removing the buffer tube. The rifle was locked up tight.
I was really stumped.
My first thought was that a lug had broken off the bolt, but once I looked at it closely, I could see the primer stuck up above the gas key.
This is why I posted this stoppage. I apologize if I caused any confusion in my initial post. I was very tired… long week this week.
We are going to run rifle and handgun tables again today, with some shotgun mixed in. I spoke with the operator of this rifle yesterday, and asked him to let me know if there were any other issues.
