AR...HELP

[TheTrainingTeamCPL]

Need some real help here fellas.

I went to shot my New AR today. When I pull the trigger it fires ( haha i know its suppose to do that) but when i release the trigger it fires another round!! WTF

Talked to Steve Fisher, gave me some ideas, but anyone ever heard of this happening?

Thanks

[Joeywhat]

Did you install everything as per this guideline?

http://www.ar15.com/forums/topic.html?b=3&f=4&t=226782

Maybe the disconnector spring was not installed?

[edge]

Most likely you have a worn trigger nose or hammer. Typically this happens when someone tries to "polish" their AR trigger to get a better trigger and wears through the thin case hardening on the nose of the trigger. This leads to a condition called "doubling".

What happens in doubling is that the rifle fires when the trigger is pulled. The bolt carrier moves back and cocks the hammer which is caught on the disconnector. As the trigger is released, the disconnector releases the hammer and the nose of the trigger catches it in a different notch. See this animation showing the AR15 firing cycle (http://www.barnesengineering.com/AR15animation/index.htm) to get a better idea of what I am describing.

If the nose is particularly worn (though use or polishing), the hammer will slip off the nose of the trigger and slam forward against the chambered round - causing it to fire. The practical effect is that the rifle fires when the trigger is pulled and fires again when the trigger is released - a condition that has obvious safety issues associated with it.

The first thing you need to do is function check your lower receiver. After unloading and making the rifle safe, remove your upper receiver from your lower receiver. With the rifle on "Fire" and the hammer uncocked, pull the trigger to the rear and hold it there. With your other hand, cock the hammer back until it catches on the disconnector (if it doesn't catch at this stage, then your disconnector or disconnector notch in the hammer is worn and needs replacing - a problem here can indicate slam firing and is even more unsafe). With the hammer cocked, put your hand where you can block the hammer from striking the magwell of the lower and release the trigger slowly. The hammer should stay cocked but should move forward slightly as the nose of the trigger catches the trigger notch of the hammer. If the hammer releases, then either your trigger or hammer needs replacing.

A function check of the fire control group is part of regular preventive maintenance and something you should do every so often while cleaning the rifle.

In any case, you can replace every component that could be causing a problem for less than $40, so I'd hold off on the Timney trigger unless you were already wanting a nice, match trigger (though match triggers are rarely as robust and reliable as the USGI trigger).

[Imshootin]

Is it new or used. I screwed up a trigger set trying to make it smoother a few years ago. Did exactly that after I worked on it. Wound up buying another trigger set.

[TheTrainingTeamCPL]

Brand new first time firing it was today.

[edge]

maybe hammer spring is in backwards...i know you said its brand new, but you still may want to check

[Imshootin]

I'd be contacting the place I bought it from first thing then.

[Joeywhat]

Could be a bad FCG. Read on arfcom a guy got a bad FCG right out of the box...

Try switching with a known working FCG, then you'll know the problem.

[TheTrainingTeamCPL]

I'd be contacting the place I bought it from first thing then.


Yeah i did they basically told me good luck seeing your rifle for a few months.



I did the whole, function test and everything functions ok. wtf

[Joeywhat]

So you pulled trigger (empty of course), then with it still held done pulled the charging handle to cock the hammer, then once the BCG was back you released?

And nothing happened?

[TheTrainingTeamCPL]

So you pulled trigger (empty of course), then with it still held done pulled the charging handle to cock the hammer, then once the BCG was back you released?

And nothing happened?

I did what the giant post above said. using just the lower.

[Imshootin]

Yeah i did they basically told me good luck seeing your rifle for a few months.



I did the whole, function test and everything functions ok. wtf

What brand is the rifle. Call the manufacturer directly. They'll probably have a new trigger group sent to you in short order. Get the problem corrected before you shoot it again. Especially these days.
http://www.gunsmagazine.com/DGR0708.html

[edge]

Troubleshooting Checklist (http://www.ar15.com/forums/topic.html?b=3&f=66&t=210213)

i don't have the attention span to do it right now, but look through the troubleshooting pages here (http://www.ar15.com/forums/forum.html?b=3&f=66&page=1) and you may find someone else with the same problem and the cause and fix

[Pnab]

I agree with Imshootin, If it is your brand new bushmaster contact them and they should be able to take care of the issue rather quickly. Also if you inform Bushmaster it is a problem that they can look for in their QC in the future.

[Imshootin]

The trigger group I screwed up a couple years ago was out of a Bushmaster rifle. If push comes to shove, they sell a new trigger group for $35.95. Part # A REHAB. Being it's a new rifle I can't imagine them not sending out the parts free of charge.

[TheTrainingTeamCPL]

Called bushmaster and they said call back on monday.

Thanks for the help guys.

[TheTrainingTeamCPL]

OK, so after some reading I've found I have a Doubling problem.

So I took my trigger group apart and looked for a piece that was worn or broke..nothing.

Did every functionality test I came across...Works properly... weird.

I cleaned everything, re lubed, and going to try and shoot it again tomorrow.

[edge]

OK, so after some reading I've found I have a Doubling problem.


i said that was your problem right off the get go at the very beginning of this thread, did you not beleive?

how many rounds have you put through it?

[TheTrainingTeamCPL]

i said that was your problem right off the get go at the very beginning of this thread, did you not beleive?

how many rounds have you put through it?

Sorry Edge, didnt see that in your post. as of right now a whopping 50 rounds.

[edge]

Sorry Edge, didnt see that in your post. as of right now a whopping 50 rounds.

no problem...has it been doubling ever since the very first round? and on the remaining 49? or was it spuratic?

[TheTrainingTeamCPL]

It seem to shoot the first25 just fine ( shot great actually) after that it went all crazy on me.

[hunt-n-fool]

if you could just get all the rounds in the mag to double........... perfection !

[Randycad]

I have a Bushmaster two stage trigger that has had a doubleing problem for a year on and off. I purchased it and shot a couple of hundred rounds through it then it started doubleing. Called Bushmaster they said you can't set it for less than 4 1/2# I told them I didn't have a trigger gauge but I followed the instructions. I then pulled it a part and found a broken spring and they replaced it at no charged. I then installed the spring and it started doubleing again I stoped shooting and adjusted it again. I will be at the range this week if the problem is still there it is in the can and I will never buy another trigger from them again.
P.S. I have 30 years of manufacturing and design experience. I should be a no brainer.:x

[TheTrainingTeamCPL]

Well shot it again today, about 50 rounds. Its all i had time for.

It shot great..not a single dang problem....maybe the gun gods are just messing with me.

[Tedfs]

Just make sure you get any doubling issues solved ASAP with your AR-15.

The feds have prosecuted individuals in the past for malfunctions that result in doubling, they like to call it a machine gun.

Not trying to be alarmist but there was a case like this in the news last year, this crap happens.