AR-15 Head Scratcher. Need Your Expertise !!!

[RoosterShooter]

I'm posting this for one of my 'Backwoods' buddies who neither has a cell phone nor internet service in today's day and time.

We took his newly self-built AR-15 to the range today and it began acting up. When you charge the handle it will fire the first round, but after the first round you have to manually 'flick' the trigger forward for it to reset.

Now, I did a standard function test of the rifle, and examined the lower to make sure that the spring for the hammer, disconnector, and trigger were arranged properly. They were.

So, this has left us scratching our heads. We fired 50 rounds through the rifle today, and the only time we didn't have to manually reset the trigger was on the 1st round of each magazine.

Any advice?

 

[Powder_Burns]

Re: AR-15 Head Scratcher. Need Your Expertise !!!

Funky disconnect or maybe the spring is upside down. Take the FCG out and look at the engaging surfaces closely. Perhaps there is a burr or something that is preventing the trigger from resetting.

 

[CL1KKL4C]

Re: AR-15 Head Scratcher. Need Your Expertise !!!

My guess is the spring was installed upside down/backwards. Especially if the Build your own lower guide from AR15.com was used. It's incorrect in their photo's.

 

[AvsFan]

Re: AR-15 Head Scratcher. Need Your Expertise !!!

1st - double check the trigger spring is installed like the picture below.

2nd - if it is? Try bending the trigger spring legs more open and that will increase the trigger spring tension. This will provide a more positive & absolute trigger reset. However, you will sacrifice and overall increase in trigger pull weight.

my $0.02

AvsFan

 

[RoosterShooter]

Re: AR-15 Head Scratcher. Need Your Expertise !!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CL1KKL4C</div><div class="ubbcode-body">My guess is the spring was installed upside down/backwards. Especially if the Build your own lower guide from AR15.com was used. It's incorrect in their photo's. </div></div>

Please refer to my first post!

All springs are arranged correctly. I inspected them myself.

I'll get with him and work on the trigger spring tomorrow. I'll let you know.

 

[Andy T]

Re: AR-15 Head Scratcher. Need Your Expertise !!!

It may still be worth to remove the FCG group, inspect it, and have you reinstall it.
Also, who made the FCG? You could replacing it with a known good one and see if the problem is fixed.

 

[Beef82]

Re: AR-15 Head Scratcher. Need Your Expertise !!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 264shooter</div><div class="ubbcode-body">Are you sure he has an AR15 bolt carrier and not an M16 carrier. Also I believe firing pins are different. </div></div>


The only difference this presents in a semi automatic platform is the mass of the recipricating assembly, if it were to cause issues it would be with carrier velocity, such as short stroking, shouldn't really effect the FCG and uses all the same parts other than obviously the carrier itself.

 

[Temp9]

Re: AR-15 Head Scratcher. Need Your Expertise !!!

AvsFan nailed it. Trigger return spring needs to be replaced or modified.

http://www.snipershide.com/forum/ubbthre...775#Post3315775

 

[McLarenross]

Re: AR-15 Head Scratcher. Need Your Expertise !!!

Both times Ive seen this issue it was the disconnector was just a few thousandths too long. Take about .003-.005" off the underside of the disconnector hook to shorten up the length the trigger needs to move before the disconnector resets and that will cure the issue. FWIW both times Ive seen this was after trigger jobs had been done to the mil-spec trigger/hammer.

 

[milo 2.0]

Re: AR-15 Head Scratcher. Need Your Expertise !!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: McLarenRoss</div><div class="ubbcode-body">Both times Ive seen this issue it was the disconnector was just a few thousandths too long. Take about .003-.005" off the underside of the disconnector hook to shorten up the length the trigger needs to move before the disconnector resets and that will cure the issue. FWIW both times Ive seen this was after trigger jobs had been done to the mil-spec trigger/hammer. </div></div>
+1 on what this guy says, I've seen it also. PM sent