Colt 6920 Jammed

AR/M4 AR Technical Discussion
1

With a little over 700 rounds thru a 4 month old 6920, I experienced a jam today. It was the last 5 rounds of the day in a 20 round P-Mag. On the last round in the mag I got a click when I pulled the trigger. The BCG seems stuck. I can not pull on the charging handle. It will not move more than 1/4 inch. I can not use the bolt assist. I can not put the safety on. There is a live round in the chamber. I’m stumped. What happened, and how do I fix this?

Ammo was .223 Brown Bear. I probably have around 350 trouble free rounds of Brown Bear thru the gun and have yet to have a problem. I was shooting M193 till this last 5 rounds of Brown Bear I put in the mag. Below is a photo taken right after the jam happened and shows the position of the BCG.

2

Mortar the round out: collapse the stock, apply force to the charging handle while smacking the stock on the ground. That will dislodge the stuck round.

3

I had the same thing happen with Brown Bear recently.
However I was able to get it free with a very light mortaring.

Never found out the cause, the round just got hung up somehow.

4

DOG SHIT ammo perhaps??? :eek:

5

Just a question…Can mortaring the round out be dangerous in this situation? It looks like the bolt is not fully closed.

6

Ive had 1 jam in 2 thousand rounds of Brown Bear and WPA at the range.
Ill take that for $160 savings

Steel cased ammo has its place in my opinion.
No its not all i shoot, and not what I would use when things matter.

7

It’ll be ok.

8

I suspect that you have a primer or anvil that has lodged itself in the cam pin area or the upper itself. It’s just a guess as it sounds like the typical symptom.

9

BCG looks really dry as well.

Whats the Lube Situation?

10

Thing looks bone dry - might try some lube…

11

Was yours well lubed up or dry when it happened?

That would definitely be a concern of mine. There is still a live round in the chamber that is not in battery. The strange thing about it is that the trigger went click just as if I was dry firing it, and it is obvious from the photo that the bolt is not in battery. I didn’t think that was supposed to happen.

Is that something that will be obvious when I get the round out?

I would say dry. Probably 300 or more rounds since I’ve lubed it. I have been wondering if that could have contributed to this jam?

12

Mine was well lubed.

There was a small dent on the shoulder of the round and a scrape on the jacket of the projectile.

13

Seriously, it doesn’t look like there’s been one drop of lube in there. Bolt and carrier look immaculate, though, even for having just 700 rounds through it.

14

So, this is something that can happen lubed or dry?

I have to wonder what the chances of the round going off from mortaring?

I’ll post a photo of the round for informational purposes if it is all marked up like that.

15

Mortaring plus THIS.

Your BCG is dryer than Barbara Steisand’s sandbox. :wink:

Any time you run cheap russian ammo, your gun needs to be weeping lube from between the upper and lower (and from the trigger pin holes).

Also, the 20 rounds PMAGs have been shit compared to the 30rounders, in my experience.

16

I’m probably a little negligent there. Last time I field stripped and lubed was July 6, 200 rounds ago. I used a good gun grease, but only on the rails. When I get the BCG out, I’m sure it will be obvious from the wear marks if the grease is all worn off.

17

It can’t fire conventionally as the bolt is unlocked, as such, given a possible broken part, the chances are no greater than with any other firearm.

18

No, it won’t be obvious. You need to look for it when you disassemble it.

19

First off. My advice is to get rid of the grease shit. Get that thing clean and put some Froglube or Slip2000 on it andf keep it WET. Not moist, not damp, but WET.

20

Nah,Impossible.
How bout the fact he was shooting that & brass cased ammo without cleaning between?

I have had the same problem on a few different brands of AR’s I own when I shoot steel & then go back to brass. (or the other way around)