Trigger wont reset!

[Stan9106]

I asked this question over on another forum and didn't get an answer. Maybe someone here can help. I just finished building a new Stag lower with a Stag LPK, a USGI A2 buttstock and buffer tube with a Wolff extra power buffer spring. Installed a new 20 inch Stag 4HL upper and took it to the range for the first time today. Ejection and loading are perfect, and the bolt locks back on an empty magazine, but the trigger doesn't reset unless I manually pull the bolt all the way to rear with the charging handle. I'm thinking maybe that Wolff buffer spring might be too strong, causing the bolt to not go back far enough to reset the trigger. Am I on the right track, or might something else be causing this? Thanks for the help!

[Robb Jensen]

Remove your pistol grip, spring and detent and the safety/selector and see if it resets freely.

If it does you can open up the notch in the safety a little more because the back the trigger is dragging on it.

[Stan9106]

It resets freely when cocking with the charging handle. It only fails to reset when firing the rifle.

[Robb Jensen]

If you have one try a different disconnector. It sounds as if you disconnector isn't releasing the hammer.

[Stan9106]

Thanks, I don't have one but I might be able to get one locally. I'll see what I can do.

[Robb Jensen]

Thanks, I don't have one but I might be able to get one locally. I'll see what I can do.

If you can't find one, send me a PM of your address and I'll send you 3 or 4 I have sitting around in my toolbox.

[Stan9106]

Ok, I did a little more troubleshooting and here's what I discovered. If I hold pressure on the trigger cocking the rifle with the charging handle, the trigger does not reset. If I release the trigger before cocking the rifle, it resets. Does that confirm it's the disconnector??

[Robb Jensen]

Ok, I did a little more troubleshooting and here's what I discovered. If I hold pressure on the trigger cocking the rifle with the charging handle, the trigger does not reset. If I release the trigger before cocking the rifle, it resets. Does that confirm it's the disconnector??

Yes is does sound like the disconnector.

When you're holding the trigger, the disconnector is holding the hammer down when you release the trigger the disconnector should release the hammer and then the trigger should hold the hammer.

When you're charging/cocking the rifle without holding the trigger back only the trigger holds the hammer as the hammer isn't in the path of the disconnector because the trigger and disconnector cam down out of the way. When your hold the trigger the disconnector is cams forward and it's notch is in the path of the hammer.

ETA - I'll get you one out today.

[Stan9106]

I have another selector. I'll put it in tomorrow and see if it works, before you go to the trouble. I let you know what happens. Thanks again for the help.

[Stan9106]

It's not the selector, as it does it with the other one installed, or even without one installed. PM sent.

[Stan9106]

gotm4, I want to thank you again for the help. I got the disconnector in the mail yesterday and put it in last night. It seems to have a much smoother finish than the one I had, and moves more freely inside the trigger. Anyway, the trigger resets now when cocking by hand. I'll take it to the range tomorrow and see how she does. Thanks again!

[Robb Jensen]

gotm4, I want to thank you again for the help. I got the disconnector in the mail yesterday and put it in last night. It seems to have a much smoother finish than the one I had, and moves more freely inside the trigger. Anyway, the trigger resets now when cocking by hand. I'll take it to the range tomorrow and see how she does. Thanks again!

Glad it worked out for you. If it's resetting by hand I'm 99% sure it will on the range too. IIRC I sent you a LMT disconnector.

[Boomer10]

I know this is an old post, but I'm having similar problems with a new upper. I recently purchased an AR57 upper and put it on my Bushmaster lower (with a single stage trigger) that I've had for about 8 years (without any major issues). I took it to the range to zero it and it would load fine, eject fine, but after the first shot it would strip a round out of the magazine and seat it in the chamber, but it would not reset the trigger. I contacted the manufacturer and they suggested I try another lower and a standard buffer (the AR57 uses a proprietary buffer). I then tried the upper on my LMT lower (with 2 stage trigger) with the same results, first shot goes bang and is ejected, second round is chambered, but no trigger reset. After this I sent the upper back to AR57 so they could look at it. They test fired about 200 rounds on 4 different lowers and it worked flawlessly every time. At this point everyone involved is extremely baffled, anyone here have any thoughts?!?



Mods, if you feel this deserves it's own thread feel free to move it.

[Iraqgunz]

I believe that I would go with the disconnector or disconnector spring. Sounds like it, but internet surgery is a guessing game sometimes.


I know this is an old post, but I'm having similar problems with a new upper. I recently purchased an AR57 upper and put it on my Bushmaster lower (with a single stage trigger) that I've had for about 8 years (without any major issues). I took it to the range to zero it and it would load fine, eject fine, but after the first shot it would strip a round out of the magazine and seat it in the chamber, but it would not reset the trigger. I contacted the manufacturer and they suggested I try another lower and a standard buffer (the AR57 uses a proprietary buffer). I then tried the upper on my LMT lower (with 2 stage trigger) with the same results, first shot goes bang and is ejected, second round is chambered, but no trigger reset. After this I sent the upper back to AR57 so they could look at it. They test fired about 200 rounds on 4 different lowers and it worked flawlessly every time. At this point everyone involved is extremely baffled, anyone here have any thoughts?!?



Mods, if you feel this deserves it's own thread feel free to move it.

[Boomer10]

I ended up getting a new upper to replace the first one (again, the guys at AR57 were very easy to deal with). I also picked up a new disconnector and spring but haven't had a chance to drop them into the lower. I took the new upper to the range today to test it out and I've come home with a different issue (which is making me think it's the lower, not the upper). I fired the first shot and it loaded the next round like the previous upper and it reset the trigger so I was starting to get my hopes up until I actually fired the second round. At that point it fired 4 rounds.:(

Nothing was changed in the lower while the upper went back to the manufacturer and the new upper came in the exact same format (16" barrel, proprietary carbine buffer, etc.) and now it wants to fire in bursts. I can either return it to the dealer I bought it from (and sell the mags & ammo) or I can see if the new parts for the lower solve the problem.

[CatmostFeared]

I have AR57 uppers and at 1st I had the wrong buffer in it.Make sure the buffer is the right lenght for your stock is correct

[CryingWolf]

Looks like they sell a couple of buffers. You never said if you have a collapsible butt stock or a rifle butt stock?


AR57-CAR "Carbine" Buffer (230g 3.5") designed for "Carbine" / "Retractable" / "Collapsible" Stock lower receivers.

AR57 - A2 Buffer (233.5g 6") designed for standard "A2 type" / "Butt" / "Rifle" Stock lower receivers.

The buffers listed on AR57 site are pretty heavy (>8 oz.)

[Boomer10]

Yes, I've already confirmed with the manufacturer that I have the correct buffer. They even had me try the first upper with a standard carbine buffer to see if that would help. It didn't so I'm on upper number 2 with issues as well.

Unfortunately this is going back to the dealer as I'm tired of dealing with it.

[dragonguard]

I'm a new guy here but I've had this problim before.
It sounds like a disconector problem.
Is your disconector spring good?
Is it properly in place?This is the first thing I would check.

Is the nose of the disconector itself in good shape...corners nice and square and fairley sharp?
Is the sharp hook on the under side of your hammer in good shape ,no burrs or chips missing?If this area is damaged it may cause the hammer to follow the bolt carrier home and with soft primers (not common with military 7.62x39) slam fire and double or run Full auto it may also cause out of battery fireing which aint cool.
Hope this helps somebody.

[Boomer10]

I'm a new guy here but I've had this problim before.
It sounds like a disconector problem.
Is your disconector spring good?
Is it properly in place?This is the first thing I would check.

Is the nose of the disconector itself in good shape...corners nice and square and fairley sharp?
Is the sharp hook on the under side of your hammer in good shape ,no burrs or chips missing?If this area is damaged it may cause the hammer to follow the bolt carrier home and with soft primers (not common with military 7.62x39) slam fire and double or run Full auto it may also cause out of battery fireing which aint cool.
Hope this helps somebody.

The disconnector and disconnector spring are both good and were checked out by a local gunsmith (who is very familiar with the AR platform).

This upper uses 5.7x28mm, not 7.62x39. Not sure if you were posting that for me or for somebody else. ;)

[dragonguard]

Yep boomer 10 it was ment for you .sorry I missread Cal.Of your upper not used to seeing the 5.7 around .
HERE is A test for your disconector to finally eliminate it as the problem.
with upper off the rifle Hammer forward...pull trigger,While continuing to hold trigger to the rear use offhand thumb to cock hammer all the way back,it SHOULD be retained by the disconector and that hook on the underside of the hammer.
Next, very very slowly take your finger off the trigger.
The hammer should attempt to go foreward but only jump a small amount and be stopped by the primary sear notch, continuing to release untill finger pressure is off should leave it in the ready to fire position if you pull back on trigger it will fall all the way foreward .
If you are doing a very very slow trigger release and the hammer flys foreward without stoping then it is not the upper .
I'll shutup now and go back to lurking.
Good luck.

[Boomer10]

Yep boomer 10 it was ment for you .sorry I missread Cal.Of your upper not used to seeing the 5.7 around .
HERE is A test for your disconector to finally eliminate it as the problem.
with upper off the rifle Hammer forward...pull trigger,While continuing to hold trigger to the rear use offhand thumb to cock hammer all the way back,it SHOULD be retained by the disconector and that hook on the underside of the hammer.
Next, very very slowly take your finger off the trigger.
The hammer should attempt to go foreward but only jump a small amount and be stopped by the primary sear notch, continuing to release untill finger pressure is off should leave it in the ready to fire position if you pull back on trigger it will fall all the way foreward .
If you are doing a very very slow trigger release and the hammer flys foreward without stoping then it is not the upper .
I'll shutup now and go back to lurking.
Good luck.

After reading your post last night I again went and grabbed the lower and already did those basic tests just to confirm it to myself AGAIN (I can't tell you how many times I've done that since I started having issues with this upper). :D

I do appreciate the help though.