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Loose primers jamming an AR

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January 06, 2018, 10:32 PM
Rustpot
Loose primers jamming an AR
Is this a common occurrence? Twice now I've had a primer render an AR completely inoperable.

Today I went to the range with a friend to kind of shake off the cobwebs. 4° and an empty range, we were just shooting into the backstop berm. I have an AR pistol in 5.56 with a 10.5" barrel that was on its first trip to the range. Gave the BCG a healthy dose of Go-Juice, dropped it in, and went through a magazine. Gave it to my friend, he got about 4 rounds in and the rifle jammed.

It was stuck slightly out of battery. I mortared it and there was an empty case in the chamber that came out. The BCG was stuck in place. Couldn't get it to budge, so I took it home.

Took it to the bench, got the upper and lower far enough apart to get the receiver extension off (pistol buffer tube with ears around the retainer pin to index the tube). Everything came apart, I found a few metal shavings in the lower and on the underside of the BCG. No apparent damage, can't find where the shavings would be from. Wipe all the parts down and the BCG slides free in the upper, locks in and out of battery smoothly, buffer looks fine, nothing suspect.

I'm reminded of the time I had an AR at an indoor range that inexplicably locked up. Finally opened up and in the barrel extension I found a badly battered primer. I told the story to my friend.

He picks up the rear takedown pin spring and detent off the floor (they fell when I got the buffer tube off) and also retrieves.... a gnarly looking primer that likely fell right along with them as everything came apart.

SOB! How often do primers pop out of brass, and if it does what are the chances of it finding its way into a critical area and cause a complete lockup of the firearm?

They were both with Freedom Munitions. No idea what the original malfunction was caused with, I could have been shooting from the same box.
January 06, 2018, 11:19 PM
Texas Bob C.
That is why military ammunition has crimped in primers.
January 07, 2018, 12:35 AM
ARman
Yep, had it happen more than once in NRA National Match Service Rifle match, it was all Federal Gold Medal brass. I quit using it because of that, it's softer than just about everything else, after one or two reloads of hot loads the primers would be loose.

I also found that Winchester is too hard, and after three reloads, if you didn't Anil the neck they would crack, neck tension would go to hell and you would get crazy shots.

For short course, I found that Remington brass to be very good. Soft enough not to work harden, but not too soft where the primer pocket would enlarge.

For long range, 1000 yards I use Lapua brass and the 600 yard line Hornady brass.

The Lapua and Hornady brass are much more consistent, but cost much more than the others, while they are beneficial in long range, they didn't offer anything at the 200 and 300 yard line that the Remington brass couldn't do.

If your brass was Federal, I say par for the course. If not, it could have been a little on the hot side. I don't know where Freedom Munitions gets their brass, if it's guaranteed to be once fired or not.

But yeah, that's why military brass had crimped primers.

Unfortunately, with the AR 15, almost anytime you pop a primer, or break a buffet detent (been there done that also~~of course during a match also~~so I know), they almost always fall into the lower receiver and get under the fire control group, tying it up. Or one time cause a dangerous triple fire condition ( during a match no less ). Eek

There is a little "receiver rug" that fits under/around the FCG (fire control group) that helps negate that. Problem is some after market/match triggers don't play well with them. You have to remove the FCG to install them.


ARman
January 07, 2018, 01:44 AM
Texas Bob C.
I read a story about an AR15 that turned into a manual single shot. A primer had come out and stopped up the gas key on the bolt.
January 07, 2018, 07:31 AM
cas
Primers should NEVER come out of the case.

If they do, you have one of three things:

1. Over pressure loads, dangerously so.

2. A head space problem.

3. Reloaded brass than has been reloaded too many times, or was over loaded at one point.



I've seen blown primers in AR's twice. Both times were people shooting 5.56 amm in .223 chambers. (see #1)

This message has been edited. Last edited by: cas,


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January 07, 2018, 07:53 AM
sigfreund
I must believe that blown primers in AR type guns is due to more than the fact that most commercial 223 Remington brass doesn’t have crimped in primers. Blown primers are a sign of excessive pressure and/or faulty brass. I see that Freedom Munitions ammunition is “remanufactured”—true? If so, that might be some of the issue. Do they use 5.56 brass whose crimped primer pockets must be reamed or swaged? Does that cause the pockets to become oversized and loose? ARman points out the differences among various types of brass, so that could be an issue as well.

I fire vast amounts of 223 ammunition, mostly Federal, without crimped primers in my ARs, and have never—ever—had a blown out primer (okay, I get it; I’ll have one the next range session Wink ).

I would be curious if the never-fired-before AR pistol in the initial post above has any problems with other ammunition. When the same problem occurs with the same ammunition, but in different guns, this old detective would call that a clue.




6.4/93.6

“Wise men talk because they have something to say; fools, because they have to say something.”
— Plato
January 07, 2018, 08:37 AM
RHINOWSO
quote:
How often do primers pop out of brass,

I have seen it twice, in my friend KelTec RFB 308, which was SERIOUSLY overgassed.

I have never seen it in many thousands of rounds in 223/556/308 out of AR15 and SCARs.
January 07, 2018, 08:44 AM
fritz
quote:
Originally posted by Rustpot:
They were both with Freedom Munitions.

quote:
Originally posted by cas:
Primers should NEVER come out of the case. If they do, have have one of three things:

1. Over pressure loads, dangerously so.
2. A head space problem.
3. Reloaded brass than has been reloaded too many times, or over was loaded at one point.

Rustpot -- assuming your gun is properly built, I'd say you have an ammo problem.
January 07, 2018, 08:45 AM
lyman
quote:
Originally posted by RHINOWSO:
quote:
How often do primers pop out of brass,

I have seen it twice, in my friend KelTec RFB 308, which was SERIOUSLY overgassed.

I have never seen it in many thousands of rounds in 223/556/308 out of AR15 and SCARs.


shot thousands of rounds thru my AR when I was shooting Service Rifle with out any issues,

98% reloads,


did have one pop out in a garand , and it got into the trigger group and locked it up,

my fault, should have tossed that brass instead of trying it one more time,



https://www.chesterfieldarmament.com/

January 07, 2018, 09:08 AM
MikeinNC
I had a blown primer jam up an AR when I was qualifying. Turned out to be reloads the department had bought for qualification/training...



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January 07, 2018, 09:13 AM
IndianaBoy
quote:
Originally posted by Rustpot:


They were both with Freedom Munitions.



This is your culprit.
January 07, 2018, 09:25 AM
CD228
As mentioned above it's a high pressure sign and should be investigated a s such. look for other pressure signs and gauge the rifle.

The other possibility is that they oversized the primer pocket while remanufacturing it.
January 07, 2018, 10:55 AM
sigfreund
There’s nothing wrong with reloads per se. When done right by a careful, knowledgeable individual who inspects everything and uses other good practices, they will be at least as good, safe, and reliable as any factory load. None of that applies to commercial reloads, however, whose brass probably won’t be processed or inspected as carefully, are subject to more variation in charges and things like primer and bullet seating, and that use brass that’s highly mixed in terms of manufacture and history.




6.4/93.6

“Wise men talk because they have something to say; fools, because they have to say something.”
— Plato
January 07, 2018, 02:09 PM
Kampy
I had the same issue with my BCM and some Independence 5.56 ammo I bought for a class. I believe the ammo was over pressure and caused all sorts of issues up to and including a primer popping out of a case and locking up the action. There was a thread started by someone else where the OP had similar issues with the same ammo.
January 07, 2018, 03:18 PM
hrcjon
I did a quick calculation of the number of rounds I've fired in an AR over (sadly too many) years and guessing about those directly around me and I've never seen one in factory ammo over what is easily a 7 figure round count. I have seen a few in reloads, and they are a b***** to clear but that's the price tradeoff.
The number of times I see problems in posts and the vendor Freedom munitions is pretty darn often.
Any loose primer bears real investigation as is noted above, it just doesn't happen. In any case I'd send the ammo back.


“So in war, the way is to avoid what is strong, and strike at what is weak.”
January 07, 2018, 06:10 PM
Rustpot
I'd send the ammo back if I could tell where it came from. I bought from them a few times, getting various weights and styles of bullets a few boxes at a time along with bulk orders of benign 55gr.

I recall it was Freedom from the first malfunction, but that was a few years ago, no idea what load. I had a partial mag with polymer tip ammo, which I've only gotten from them, and put it in the pistol yesterday.

The first mag I shot through the pistol was 55gr M193 ball ammo.

I attributed the failures to remanufactured ammo. The price for cheap ammo. I have to take a detailed ammo stock to see if I have anything left from them, too much to keep track of when I went dormant from shooting for a few years. I know I have a few boxes of various .308 loads from Freedom.
January 07, 2018, 06:30 PM
mercedes560
I've had that, using federal brass reloads I had a gas key on my 20 inch upper get filled with FIVE spent primers. If I hadn't seen it and drilled them out myself I wouldn't have believed it lol
I'm most shocked it worked up to the fifth one!

Federal brass gets max 3 loadings now.
January 07, 2018, 06:59 PM
djpaintles
As mentioned a couple times before this is why Military rounds have crimped primers....

It’s also why I don’t shoot hot loads and I NEVER shoot any reloads except my own.


Remember, this is all supposed to be for fun...................
January 07, 2018, 07:51 PM
captain127
Another contributing factor can be if you are reloading military brass and get overzealous removing the crimp causing loose primer pockets
January 07, 2018, 11:10 PM
cas
It's generally accepted that crimped primers are to keep this from happening in machine-guns with questionable headspace. But reality is crimped primers (military and non) date back to the late 1800's, before full or semi auto weapons.


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Sliced bread, the greatest thing since the 1911.