Norinco M14s trigger resets with dummy rounds but not live ammo

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chalk talk

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Hello all,

I hope some of you can offer some insights on a Norinco M14S trigger resetting issue. The rifle is sitting in an American glass stock with the popcicle stick completed and the glass shaved on the right side so the receiver sits squarely on the stock. It worked with dummy rounds: trigger resets correctly and passes safety tests. It worked for about 100 rounds (7.62 x 51 Norinco) at the range and then the rifle stopped resetting the trigger. The bolt would cycle and rounds would feed but the trigger would not be reset.

I figure that I need to shave a little more glass so that the trigger pack pads sit higher in the receiver. The curious thing is that the trigger continues to reset perfectly with the dummy rounds (.308). Why would that be the case?

Thoughts?

Thanks
 
Not sure why that's happening but have you done the trigger after assembly test on it ? This will let you know if more material needs to be removed from the trigger pads on the stock. Very important that it passes this test or slam fires may occur

1. #### the action and test the safety
2. Release the safety and fire the action .
3. #### it again keeping the trigger pulled top the rear .
4. The hammer should stay to the rear and not follow the bolt forward.
5. Release the trigger and you should hear a click , then squeeze trigger and the hammer should release.

Do this a few times to ensure the hammer stays to the rear when cocking the action with the trigger pulled to the rear.
 
chalkriver said:
Not sure why that's happening but have you done the trigger after assembly test on it ? This will let you know if more material needs to be removed from the trigger pads on the stock. Very important that it passes this test or slam fires may occur

1. #### the action and test the safety
2. Release the safety and fire the action .
3. #### it again keeping the trigger pulled top the rear .
4. The hammer should stay to the rear and not follow the bolt forward.
5. Release the trigger and you should hear a click , then squeeze trigger and the hammer should release.

Do this a few times to ensure the hammer stays to the rear when cocking the action with the trigger pulled to the rear.
Click to expand...

Chalkriver,

It passes these tests (all five) with the dummy .308 rounds and without the dummy rounds even now. At the range, no problem for 100 rounds and then the live ammunition chambered, but trigger not reset.

Pressing the trigger yielded no results - no click and it was obvious that the sear was not engaged. Pulled back the charging handle, unfired round ejected, released handle (no riding the handle), final round chambered but trigger not reset again. I appreciate that this rifle is currently unsafe and not to be used as there is a potential for an out-of-battery kaboom.

I think the trigger pack needs to be placed closer into the receiver to allow for a more positive sear engagement during cycling (but this is my guess and I'm no expert.... but I am having fun). I found it interesting that it passes all safety function tests with the dummy rounds but not function with the norinco ammo after 100 rounds. Could it be the result of Norinco ammo/ dummy dimensional differences, cycling issue with live ammo (i.e. something like short cycling due to something hanging up the cycle)?

It is a 2007 vintage rifle that I finally got a chance to shoot after collecting dust in the safe for almost a decade. Another 2007 with a Boyd's stock functioned perfectly for 300 rounds with the same ammo including those that did not fire in the first rifle.

Somewhat puzzling I say...

additional info: gas system passes tilt test, no wear marks on barrel or stock on from spring and op rod guide, bolt looks normal with no wear marks, trigger pack looks normal with no worn or rounded hooks. Hooks look square and sharp.

Ideas? Thanks.
 
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hows the trigger guard lock up. too loose and the hammer may not come back far enough to catch the sear. you can take the receiver out of the stock , and hook up the trigger, just to see how things work. I don't have the answer , but tonyben on u tube is your friend. grumpy ACP 45 was excellent for this stuff, but he don't visit no more.
 
Sounds like a short stroke.

You figures it happens after about 100 rnds of live fire? Seems a bit "light" to completely foul up a gas system.... Do you clean the gas system after every range outing, or just once ina while?

Cheers!
 
Try rifle in the other stock if ok stock issue. trigger group maybe seated too deep in stock or not deep enough, They seem to be really sensitive to this. Try some electrical tape between the trigger group flange that will tell you if sitting to deep. or try other trigger group.
By what you said earlier you have an other rifle?
 
1-trident-1 said:
hows the trigger guard lock up. too loose and the hammer may not come back far enough to catch the sear. you can take the receiver out of the stock , and hook up the trigger, just to see how things work. I don't have the answer , but tonyben on u tube is your friend. grumpy ACP 45 was excellent for this stuff, but he don't visit no more.
Click to expand...

Thanks for the input. Trigger guard lock up is tight. A wee bit tighter than the original chu wood. I need to place the shaft of a screwdriver into the hole in the trigger guard to open it.
 
notsorichguy said:
Sounds like a short stroke.

You figures it happens after about 100 rnds of live fire? Seems a bit "light" to completely foul up a gas system.... Do you clean the gas system after every range outing, or just once ina while?

Cheers!
Click to expand...

Rifle was new and had been cleaned. Gas system was dry. Passed the tilt test after it malfunctioned - no binding whatsoever. I took apart the rifle to check for evidence of binding but I don't see any wear. I guess I'll revert to the original op rod guide just to check out if somehow the spring is binding with the round op rod from NE Arms (maybe this is the maker.. I can't remember.. round op rod with grooves).

Thanks for your suggestion.
 
wce323078 said:
Try rifle in the other stock if ok stock issue. trigger group maybe seated too deep in stock or not deep enough, They seem to be really sensitive to this. Try some electrical tape between the trigger group flange that will tell you if sitting to deep. or try other trigger group.
By what you said earlier you have an other rifle?
Click to expand...


Thanks for the tape idea. I'll try that to see if I can get it to malfunction with dummies. I think I'm just on the edge of it being reliable and the tape will confirm which way I need to go.

I guess that I should start with a stock swap and then test. If it passes, I will work on the American glass stock. If it fails, I'll do a swap of trigger packs and place in the original chu wood stock. If it passes, there is an issue with the original trigger pack, if it fails it becomes a parts gun.


Will keep people posted as to results.
 
chalk talk said:
Rifle was new and had been cleaned. Gas system was dry. Passed the tilt test after it malfunctioned - no binding whatsoever. I took apart the rifle to check for evidence of binding but I don't see any wear. I guess I'll revert to the original op rod guide just to check out if somehow the spring is binding with the round op rod from NE Arms (maybe this is the maker.. I can't remember.. round op rod with grooves).

Thanks for your suggestion.
Click to expand...

Try a small diameter drill bit or Allen key to see if you have good clearance from the gas port to the gas cylinder.

You should be able to pass a 5/64 drill bit straight through the gas cylinder into the barrel. Use the "dull" end of the drill bit!

I have never seen a trigger pack cause short stroking on a '14.....

Cheers!
 
I forgot to say that it was lubed. Lubed with Mobil 1 synthetic grease. No problems with lube on the bolt, op rod and bolt roller. The more I think about it, it does seem to be short stroking for some reason.

I appreciate the input. Thanks!
 
notsorichguy,

I took apart the gas cylinder. The gas plug was not as tight as I would expect. Secondly, the gas system rattled a little after the figure "8" shaped cylinder nut was removed. It too was looser than expected. It seems that a few shims have been pushed out of position (had to cut them as the only way to insert them without cutting was to remove the flash hider... haven't done that yet)

5/64" drill bit will enter the gas cylinder. Only a 1/16" will enter the gas cylinder and barrel. The hole in the barrel is not 5/64". I have no idea about this. I have tried a couple of times.

Replaced old shims with new shims and made sure that the 'figure 8' lock nut stops at 3:00 and that I have to push like hell to get it to 6:00. Gas system is now tight with no movement. This might be part of the solution.

I'm still confused why that when manually cycling the bolt, the same trigger non-reset happened. That doesn't seem to suggest a problem with the gas system. But notsorichguy was correct, the gas system was not perfect to say the least. Perhaps, I need to start looking at the stock/ trigger pack fit.

Any suggestions are really appreciated!! I thank everyone again!!

Any and all ideas are appreciated. What a fantastic forum for enthusiasts!
 
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The fact you can duplicate the malfunction by hand certainly leads away from the gas system.
There must be some interference with the hammer not coming all the back to catch on the primary sear.

Pull your trigger group out and check your hammer and trigger pins havent walked out.
If they are in properly, perform the safety check with just the group and operate the hammer by hand. While holding the trigger back, #### the hammer all the way down and let go, it should get captured by the primary sear.
If it fails then your housing my be bent or out of spec in one way or another. If it passes then pull your stock off and set the trigger group in place in the stock, where it would be if locked up with the receiver. Check for stock to trigger group interference along the vertical sides by the trigger and sears, and also check that you hammer doesn't touch anything.
If all clear then your group 'height' in the stock may be off and either needs to be raised or lowered.

Try the first few checks first and if all passes then we can discuss the trigger group height in the stock.

Good luck

Jon
 
grumpy 45acpking who doesn't post anymore because he's tired of the internet , and grumpy for the past few years because a few m14 related businesses and 1 ex cgn mod, decided to screw me over at every turn during my time here..... I think the only reason I didn't get banned here like so many others is simply due to the fact that my sharing of knowledge in the m14 circles, kept the site's traffic up hahahaha :D

as for the OP's "trigger problem"..... I'd tune out all the other advice in this thread, that tho well intended, takes one down the rabbit hole and away from the problem. Folks here would be very wise to start heeding Notsorichguy's suggestions, as a "lurker" these days, I see the advice he gives as being closer to hitting nail on head than most.
so with that:
If it takes 100 rounds to start having a problem, it's not the trigger, nor is it lack of grease, nor is it the stock.
if it passes the hammer follow test repeatedly with or without dummy rounds (the test should be performed with an empty chamber at all times by the way) , it's not the trigger group nor the stock.
if it takes many rounds for a problem to start and that problem is a failure to reset the trigger after the shot, it's a classic short stroke and all attention should turn to the gas system. The fact that it functions "cold" but after many rounds starts to fail as the metals heat up..... tells me to also look the gas system.

there ya have it, probably the last M14 advice you guys are gonna get from this grumpyphucker LOLZ
 
45acpking,

Thanks for pointing out the gas system. Doing all these modifications myself, I may have created several issues for myself. I've taken apart everything and checked trigger pack function, op rod binding is not an issue, op rod guide and spring is functioning with no binding, no loose parts anywhere. I've made sure that the gas system is on tight and that a 1/16" drill bit shank fits through the gas cylinder and barrel (5/64" will fit the gas cylinder only). The gas piston (terminology?) was not full of carbon (as it was new) and is dry and passes tilt test (takes a couple of seconds when the barrel is cold).

I will see if I can replicate the problem. If it fails after it is hot, I'm doing a tilt test and breaking down the gas system to check what is happening as a starting point. If it fails when cold, well I guess it is time to start looking at everything suggested.

Time for a range trip. I'll let everyone know how it goes.
 
My apologies to the OP for potentially sending you down the rabbit hole.
My understanding was the problem was duplicated when dry cycling the action.

At the very least, the additional checks the OP has been lead to perform has made him more comfortable with the rifle and everything is a learning experience, hopefully some value can be found in that.
 
No apologies required. I think there may be more than one issue at play. After failure of trigger reset with live ammunition, trigger reset failed again on manually pulling back the op rod and letting it fly. Each suggestion gave me further insights into how to make this a reliable rig.

Cheers!
 
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