My new AR double fires - HELP!!

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[ARCHIVED THREAD] - My new AR double fires - HELP!!

Posted: 9/27/2004 4:33:25 PM EDT

Hi all,
I just finished putting together an AR15. I went to the range to test fire it, and it shoots two rounds with one trigger pull. If I put three rounds in the mag, the first two will fire with the first pull on the trigger. The third round chambers but the gun is not "cocked" (the hammer is in the fired position). What is wrong and what can I do about it? I will very much appreciate any help.
Thanks in advance.

Posted: 9/27/2004 4:54:48 PM EDT

[#1]

What type of trigger is it Single stage or Two Stage and what make.

Posted: 9/27/2004 5:09:42 PM EDT

[#2]

Did you use quality trigger group parts, or just a no name kit?

Sounds like worn parts, probably the disconnector. I wouldn't fire it any more until you've got it figured out. If the hammer is following the carrier forward rather than being caught by the disconnector, you could have a serious kaboom if fires out of battery.
This is why I only use good parts (Bushmaster, RRA, Colt, etc., but especially Bushmaster) and leave the gunshow bin parts alone.

Posted: 9/27/2004 6:16:41 PM EDT

[#3]

Guys,
Thanks for the replies. The trigger is a single stage, just stock, from RRA with the JT yellow springs. I took it out of my other AR and it always worked fine in it. Could putting the original full power springs back in help?

Posted: 9/27/2004 6:23:24 PM EDT

[#4]

I've had that happen before.

The second shot is happening when you release the trigger, the solution is to trim a bit off the front of the disconnector (where it touches the TRIGGER) to increase the engagement of the disconnector and hammer so the trigger catches the hammer when the disconnector releases it.

Posted: 9/27/2004 6:51:09 PM EDT

[#5]

Quoted:
Guys,
Thanks for the replies. The trigger is a single stage, just stock, from RRA with the JT yellow springs. I took it out of my other AR and it always worked fine in it. Could putting the original full power springs back in help?

Give the full power springs a try for sure! If nothing else, it won't cost anything.

Posted: 9/27/2004 7:06:21 PM EDT

[#6]

take the lower off and let the hammer forward. slowly pull the trigger and watch how the parts interact as you move the hammer between them. if at any time you can release the trigger and the hammer doesn't catch as the disconnector releases you have a problem with worn parts, or the holes in your new receiver arn't quite spaced correctly. if the trigger works fine in a different gun then the latter may be the case. you can measure the spaceing with a caliper.

also make sure your fireing pin is moving freely. (not stuck foreward)

Posted: 9/27/2004 7:51:47 PM EDT

[#7]

Dude, that's not a problem, it's a feature!

Posted: 9/27/2004 8:29:48 PM EDT

[#8]

Well, the disconnector is catching the hammer, however, it fires when you release the trigger, and this is caused by the hammer not being "caught" bu the trigger.

First and foremost, ensure you installed the hammer correctly (make sure both legs of the spring rest on TOP of the trigger pin)..... and ensure you have the small coil spring between the disconnector and the trigger bar.

Barring that, I would swap the FCG.... call up RRA, they should send you a new FCG.

Posted: 9/28/2004 2:58:28 PM EDT

[#9]

Quoted:
Well, the disconnector is catching the hammer, however, it fires when you release the trigger, and this is caused by the hammer not being "caught" bu the trigger.

First and foremost, ensure you installed the hammer correctly (make sure both legs of the spring rest on TOP of the trigger pin)..... and ensure you have the small coil spring between the disconnector and the trigger bar.

Barring that, I would swap the FCG.... call up RRA, they should send you a new FCG.

Inspect to be sure hammer spring is inded holding the trigger pin in place, had another member her install spring incorrect, and trigger pin kept popping out the side of the lower, he was ready to send the thing back, but I looked and repaired in less than 5 minutes there at the range, he was able to finish the day.

Adjust the disconnector for slight deeper engage to hammer, it is letting go of hammer too early, and primary sear is not yet in line to catch the hammer.

Repair should take you no more than 15 minutes, and cost you nothing.

Posted: 9/28/2004 4:16:31 PM EDT

[#10]

Thanks so much for all the help. I took the trigger group out and found that the disconnector was lodged solidly in the slot in the trigger. I don't how it got there or why it got stuck, but I popped it out, pollished the sides of the disconnector, put everthing back together and it works great. Again, thanks - I was sure I would get the help I needed here!!!

Posted: 9/28/2004 4:19:37 PM EDT

[#11]

I wish my ar did that!

Posted: 9/29/2004 2:42:00 AM EDT

[#12]

Well on my first AR build I started to get doubles and even three round bursts, it was very cool at first but I figured I better fix it. I found the cotter pin in the bolt that keeps the firing pin in place had one leg curled up on the inside of the bolt that was rotating around. Well that leg would turn forward and keep the firing pin forward all the time untill it rotated back again.
My guess is whoever built the bolt just jammed the cotter pin in causing the leg to curl on the other side of the bolt.

Posted: 9/29/2004 7:46:37 AM EDT

[#13]

Quoted:
Well on my first AR build I started to get doubles and even three round bursts, it was very cool at first but I figured I better fix it. I found the cotter pin in the bolt that keeps the firing pin in place had one leg curled up on the inside of the bolt that was rotating around. Well that leg would turn forward and keep the firing pin forward all the time untill it rotated back again.
My guess is whoever built the bolt just jammed the cotter pin in causing the leg to curl on the other side of the bolt.

Damn those are slam fires... very dangerous.

Posted: 9/29/2004 8:34:40 AM EDT

[#14]

Quoted:
Thanks so much for all the help. I took the trigger group out and found that the disconnector was lodged solidly in the slot in the trigger. I don't how it got there or why it got stuck, but I popped it out, pollished the sides of the disconnector, put everthing back together and it works great. Again, thanks - I was sure I would get the help I needed here!!!

Was it stuck down in the slot, where the trigger pin goes through, or was it stuck in the back part of the slot, where the disconnector spring is supposed to be installed? I'm wondering if you're missing the disconnector spring. If that spring is installed it should keep the disconnector pivoted forward and not allow it to pivot back far enough for the back part of the disconnector to get stuck in that slot. If there is no spring in there then it can pivot back and may not catch the hammer. I'm wondering if this is your problem.

Posted: 9/29/2004 8:59:13 AM EDT

[#15]

Here is the coil spring he and I were referring to... make sure this is installed!!! Look in the trigger assembly..... is yours there?

Posted: 9/29/2004 3:34:41 PM EDT

[#16]

Fellows,
Yes, the disconnector spring was installed, but the tail end of the disconnector was stuck in the slot in the trigger assembley. Everything is fine now.
Thanks

[ARCHIVED THREAD] - My new AR double fires - HELP!!

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