# AR-15 double firing



## barbless (Jul 27, 2004)

About once every 20 - 30 rounds my DPMS double fires. I'm using Winchester primers and I'm wondering if they're very sensitive to the firing pin poking them once the bolt slams home since it's free floating. Or could it be the interrupter malfunctions? Rifle shoots great, down to 1/4" groups shooting Sierra 65 gr game Kings and Varget.


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## jamisjockey (Jul 30, 2009)

When is the last time you've completely cleaned the bolt carrier and bolt? Sounds like your firing pin is sticking forward. 
How many rounds through the gun approx.?


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## barbless (Jul 27, 2004)

maybe 100 rds since complete cleaning. Didn't think of firing pin sticking forward.


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## THE JAMMER (Aug 1, 2005)

That happened once with my M1A. Gets your attention. First of all what do you have your trigger set at. If it is really light, you might be leaving your trigger finger back after you fire, causing a slam fire- that's according to Kerry at Match grade. We lightened my trigger a bit, and I was more careful with my trigger finger, and problem solved.


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## Trouthunter (Dec 18, 1998)

Clean the bolt assembly...firing pin may be sticking out of the bolt.

Had that happen on an SKS...nothing like 10 rounds going off rapid fire and me not being prepared for it. 

TH


Jockey just saw your post...


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## jamisjockey (Jul 30, 2009)

THE JAMMER said:


> That happened once with my M1A. Gets your attention. First of all what do you have your trigger set at. If it is really light, you might be leaving your trigger finger back after you fire, causing a slam fire- that's according to Kerry at Match grade. We lightened my trigger a bit, and I was more careful with my trigger finger, and problem solved.


True. I've had this happen to me when I was working on feeling my trigger reset. My 20 barely recoils, but the carbine kicks a touch more. Worth looking at the software as well as the hardware....


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## txdukklr (Jun 30, 2013)

my first thought is how light is the trigger for recoil fire, second is a stuck firing pin.

Not that this necessarily matters but is your bcg a milspec or commercial grade. Any gun I've had with a commercial I pitch and replace with a heavier milspec. Also gets run very very wet. Especially when I'm in a case depleting zombie killing practice session with paper.


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## barbless (Jul 27, 2004)

I'll clean the bolt and carrier. If I'm understanding you correctly, there's no way I can let off the trigger before the rifle has the next round chambered. Isn't that what the interrupter in the trigger group is for, to stop full auto?


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## jamisjockey (Jul 30, 2009)

Not quite. What we're saying is if you keep the trigger pressed to the rear and release it too slowly, that sometimes the human reaction is to pull the trigger again and if you've hit reset, it'll fire again.
If you have a target trigger, they're lighter than a regular trigger and even easier to set off again.
Just an idea, anyways. 

Oh and txduk brings up another point. Make sure you're running it lubed well. Pull the bolt, scrape any carbon off the back of it behind the rings, make sure the inside of the BCG is clean and the pin too. Then lube it all before you put it back together. A sloppy wet BCG is a happy BCG.


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## CHunter (May 25, 2004)

Agree with the others......


Clean the bolt carrier group and firing pin. The bolt carrier is real bad about carbon build up.

If it still happens change primer to a #34 CCI, they have a little heavier cup to prevent the slam-fire.......if that's whats happening


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## barbless (Jul 27, 2004)

I took the AR apart over the weekend and cleaned her up; it wasn't that bad. The BCG was not bad and the firing pin was not sticking. I think I'm getting a slam fire every so often. If I can find them I'm going to try the CCI primers; I think the Winchester primers I'm using are too sensitive. Thanks for the replies.


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## barbless (Jul 27, 2004)

Mr AR at work told me to stretch the disconnector spring cause the disconnector was failing to hold the hammer when the trigger was still depressed after firing. I did that and last weekend ran 20 rounds through it quick and it never doubled. Halleluiah!


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## larrymac1 (Dec 8, 2011)

*Try Academy*



barbless said:


> I took the AR apart over the weekend and cleaned her up; it wasn't that bad. The BCG was not bad and the firing pin was not sticking. I think I'm getting a slam fire every so often. If I can find them I'm going to try the CCI primers; I think the Winchester primers I'm using are too sensitive. Thanks for the replies.


The past few times I was in Academy they were carrying CCI primers for everything except magnums. Usually on an endcap by the firearms. They don't sell bricks but single packs at about $3.49 which is not too bad. I have seen a lot worse.


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## Ernest (May 21, 2004)

Winchester small rifle primers have a thicker cup than CCI 400's. Cup height is the same. CCI 450's (mags) have a thicker cup. 

Fed 200's - .019
CCI 400 - .020
WSR - .021 
Fed 205m's - .0225
CCI 450's - .025. 

I've run 1000's upon 1000's of Winchester small rifle primers thru the AR 15 platform without any slam fires. So have tons of other people. I've also ran 1000's upon 1,000's of CCI 400's thru the AR 15 platform. Again, no slam fires. So have a bunch of other people.


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## Bantam1 (Jun 26, 2007)

I got hear too late but I was going to say check your disconnector and/or spring. It sounds like you have it figured out. 

If you are really worried about slam fires you can use the CCI #41. They are the "milspec" primers with a harder cup (or so they advertise). I have run just about every brand and style and have never had a slam fire. I run the Fed GM primers in my precision AR with no issues.


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