M14/M305/M1A Test after assembly

can we maybe describe this situation in proper terms here: not full auto firing but actually slam firing.
there is really some controvercial stuff going on with another rifle out there and we know the boys in blue watch this site and are members.
lets not give them more to think about taking away.
full auto is a term used for proper timing and lock up of bolt
slam firing is a condition that is unplaned, and is unintended, which could result in serious injury to person and bystanders. which i think best describes the situation here.
just my 2 cents
 
Good point and my post is edited. It's not Full-Auto in correct terms, but an unsafe trigger. I always thought slamfire was a stuck firing pin or firing out of battery before the bolt lugs were locked causing an even more dangerous situation than an unsafe trigger.
 
I have recently purchased a SA Fiberglass stock for my baby. I switched the stocks around and now when I lock up the trigger group (no extra pressure applied, goes on no prob.) my action gets stuck halfway. The barrel was indexed at M14Doc's clinic so that is not the issue. I think I might have to shave some of the stock down but would like to hear your opinions BEFORE I start doing anything.
 
anonovic.aleksandar said:
I have recently purchased a SA Fiberglass stock for my baby. I switched the stocks around and now when I lock up the trigger group (no extra pressure applied, goes on no prob.) my action gets stuck halfway. The barrel was indexed at M14Doc's clinic so that is not the issue. I think I might have to shave some of the stock down but would like to hear your opinions BEFORE I start doing anything.
Click to expand...
Sounds like either the trigger pad area might need some attention or the reciver flat on the top part of the stock might need some attention. Please post some pic's as it will be easier to figure out were this binding might be occuring.
 
I found that the receiver on my new shorty is a different dimension than my other 2 polytechs and it is different than a couple norinco,s that I tried as well.

My shorty would not fit in 2 USGI stocks that I have , but the polys and Reg Norincos went in all right. I had to remove quite a bit of material under the trigger guard and the trigger pad area and now its fine.

The areas in white are where I removed material , I took off a little at a time and did the trigger assembly test after I removed some material each time.



Shorty1c.jpg
 
I'm having this same issue with my norinco m14. Although its had a few hundred rounds through it with zero issues. I've removed material in the places suggested but still fails. I noticed there's a small gap between the back of the receiver and the top of the stock. The back of the receiver seems to be lifting from the stock when the charging handle is cycled. If I hold the receiver and stock together with my hand and perform the test it passes every time. Any ideas what to do next?
 
Just a heads up to anyone who is planning on buying the M305 with the desert digital camo stock. A few vendors have them for sale. I had to shave a good ~1/4 inch off the trigger group bed at the bottom of the stock and both sides where the "wings" on the group sit.

I've read on here and on m14forum that you should shave off at most a few hundredths of an inch. I did this and there was no change to the hammer follow. I shaved very small amounts off and reassembled probably 15-20 times before I got it working perfectly. Also, a good tip is to fit the trigger group in the stock before a full reassemble just to be sure that there's no wobble between the three spots you're shaving.

Just goes to show you even brand new never-fired rifles can have this issue.
 
Sniper1 said:
This thread is so important !

My Norinco M14S is very prone to this problem of the sear not catching the hammer, when pressing fully the trigger while cocking (let's call it the "M14 sear bug").
Here's the story :
- in chinese wood = no problem
- in USGI fiberglass stock = sear bug. Bug eliminated by slightly filing the ledge on the bottom of the stock where the back end of the trigger group sits.
- in Troy MCS chassis (MOD 1) = sear bug again.

Now my hesitation is with filing my Troy MCS chassis. Reason 1) it very expensive. I don't want to ruin its resale value. Reason 2) it does have trigger group adjustment screws (try them, but doesn't help)... could there be another detail, tip or trick i'm missing with the MCS Mod 1 system ?
Is there another way to get rid of this "sear bug" ? ex: filing the back bottom lip of the trigger group to reduce its thickness ?

Pic of the "sear bug" with my M14s in Troy MCS
http://img.photobucket.com/albums/v517/Sniper918/M14 Troy MCS/2009_0701_000323AA.jpg
Pic of the portion of the stock that I should be filing down (but as mentionned above, i would greatly appreciate some advice to an alternative solution). Notice the adjustment screws are slighly exposed. However, if i raise them more, it just causes difficulty to lock the trigger group in place, with no positive effect on the "sear bug".
http://img.photobucket.com/albums/v517/Sniper918/M14 Troy MCS/2009_0701_001059AA.jpg
Here's when I drop the trigger group in place. I have the required 1/8" clearance between trigger and guard (per Troy instructions).
http://img.photobucket.com/albums/v517/Sniper918/M14 Troy MCS/2009_0701_000931AA.jpg
Trigger group in place. Looks normal. However, I can't shoot it like that. too dangerous.
http://img.photobucket.com/albums/v517/Sniper918/M14 Troy MCS/2009_0701_000737AA.jpg

Any advice ?
Thanks
Click to expand...

M14 Sear Bug is a great label for it, and I wonder if it's just with Norcs, or can it happen with the Springfield's as well.

My rifle will not pass the function test when the trigger group is mounted in the rifle. It’s able to work outside of the stock, but once mounted into the stock, the trigger will not “reset” (rack the bolt, squeeze the trigger, continue to squeeze, rack the bolt again, release the trigger and it should reset – but it does not).

My buddy ground down the area on the plastic stock where the trigger rests in the stock, and it didn’t resolve the issue. We thought that because we messed with the stock so bad, that the stock was the reason it was failing to reset, so we tried the receiver and trigger group in two other Norinco rifle stocks, as well as a USGI stock, but the trigger group would not fit any other stock. I’ve had a few people look at it and they’ve all been stumped.

We then filled the area back in with some sort of putty/compound and tapped in an adjustable set screw, and it worked for a while, but I think it only worked because it didn’t allow for a full trigger pull. What I noticed, with the trigger group out and dismounted from the rifle, was that that the trigger resets either with the trigger fully depressed, or barely depressed. When mounted in the rifle, the trigger resets only when the trigger is semi depressed, but not fully depressed. Anyway, I think the putty/compound was a temporary solution as it didn’t allow for a full trigger pull. It did allow enough pull to release the hammer, and allowed the sear to sit at just the right spot to reset the trigger when the bolt came back, but when the putty fell out, it stopped working again.

Will have to tinker around with it a bit more.

*UPDATE JULY 28th, 2013*

I am an idiot. I assumed that because we already milled out the area where the rear of the trigger group sits, my problem was different....but it wasn't. took the trigger group out of the stock, as well as the receiver. I assembled the two together, tested it, and it worked fine. I rough measured the top of the receiver to the bottom of the trigger guard, then I reassembled everything back into the stock, and it was about an eighth of an inch taller in the stock.

So I took chisel to it (no dremel), started hacking a way, little by little, and now it functions fine. Post #5 in this thread is absolutely right, 95% of the sear bug issues can probably be resolved by post #5...thanks!
 
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This is a great thread for those of us changing the stock on the Norc M14. I just received and installed a Boyd's walnut stock on my Norc. As per post 26, I chiseled small amounts as indicated by Chalk River for the action to fit properly. As per post 5 - sure enough, it failed the sear test so I removed a a small amount of wood at the trigger inlet as indicated by Brobee and the trigger reset just fine after that. A lot of aggravation was avoided.

Thanks Chalk River! Thanks Brobee!
 
I just put an M305 into a McMillan MFS14 and ran into the Sear Bug.

I used the exact fix shown by Brobee in post #5, took off 2 hundredths of an inch (1.72" to 1.70") and it runs perfectly.

Thanks ya'll!
 
I called Sage about this problem. Their stand is that the hammer safety test has no merit in the Sage EBR. They did a study on this problem and a white paper was written by expert gun smiths describing why it was not a problem in the EBR Sage stock.
 
Mine just flunked.

I just swapped out my old rat USGI stock for a new walnut Boyds on my 305 and it failed this important safety function check.
I'll take a look at the new stock-trigger group interface. I perform this check every time I reassemble my rifle and it's never failed before.
Thx for the diagnosis and possible fix!
 
I feex heem!!

Yup, #5 did it for me too.
I just finished dropping my Norkie into a Boyds walnut.
After lots of measurin' an' 'spectin' I took a 1" flat file to those places where the "wings" rest.
I filed it until the stock was flush w/ the liner--it only needed about ~1.0mm.
Then I broke out the dremel and mounted a smallish sanding drum. The drum was the perfect
size to fit into that rear inletting. I figured I'd sand & try, sand & try...but NO, it did not require
much at all--maybe 0.5mm or less: It fit in on the first try and passed the function test easily.
'Whew, ya! Life is good whenever you find Murphy asleep at the switch. The fix turned out to
be way easier than I expected.
Now I have just to do The Popsickle Stick Trick and I'll be out at the range faster than a speeding bullet.

Is this thread a Sticky? If it's not, then it dam sure ought to be.
And, YES, full marks to both Brobee and Chalky!
 
Ok, I have the sear bug issue.

Here is the situation.

I have a Norinco M14 (2009). Trigger group is Norinco, oprod and barrel too.

I installed the following upgrades:
Springfield NM Flash Hider
USGI NM Front Sight .062"
USGI NM Rear Sight with hooded aperture
SEI Gas Cylinder
SEI Gas Piston
USGI Gas Plug
USGI Spindle Valve
Sadlak Spring Guide
Wolfe Operating Spring
SEI Extended Bolt Release
USGI Handguard
Boyds Walnut Stock

I installed all the above with the help of Barney (aka TacticalTeacher or Hungry). We also bedded the action into my Boyds stock.

Since then I went to the range. I had 2 double-firings.

I went home and reloaded 30 rounds with reamed and deepened primer pockets. I know this is important for slam-fire avoidance. All primers (CCI Large Rifle), were .005" below flush.

2 more slam-fire doubles...........

I checked the rifle over, and observed that the sear didn't engage the hammer when the trigger was depressed and the bolt was cycled.

Did some checking on this forum, and I came across this thread. Very helpful.

This morning, I called Barney, and apprised him of the situation. He suggested I swap trigger groups with as many other Norinco rifles as buddies would lend me. Problem is; I don't have any.

I was reluctant to sand down the bedding I had just done. Seems backwards that I should loosen up my tight fitting bedding because of crappy QC in China. However, I like my face and has the way they are, without bits of by gun embedded in them. I also like my gun to much to turn it into several pieces of twisted metal and splintered wood.

I took a bit off the rear of the trigger guard as post #5 suggested.

I performed the test again. That's when I noticed something.

If I depress the trigger, pull the oprod back for the entirety of its travel, and ease it into battery by manually letting it forward, the sear doesn't catch the hammer. HOWEVER, if I depress the trigger, pull the Oprod back, and "slingshot" it forward by merely releasing it crisply, these are DOES engage. Every time.

If I ease it forward in the least (I mean even 1/8"), and then release it, back to the not engaging story...

Problem is, I never tried "slingshotting" on my initial test. Not sure if this measured partial success is due to the removal of material I just did, or if I haven't changed anything...

I leave for a moose hunt Friday morning. I am still developing a load for this rifle, and haven't sighted it in.

I have a USGI trigger group in the mail as we speak, but it won't get here in time.

What do I do? Is it safe now? Do I take more off?

Needless to say, ASAP is an understatement. As the tag holder for my group, I need to go. I have to have a safe reliable firearm that I trust and am confident with.

Thanks for your help guys!

Alec
 
It would be a shame to shave down your stock to suit the current triggger group when you have another on the way.
 
Pass test or Savage

I can certainly understand your disappointment with your rifles' failure to function safely after having done all those modifications to it.
But Longshot, your remedy may be quite simple-- here's an important question: Did your rifle pass the function test, and was it performing correctly before you made all the mods? If it was working fine then it's not down to any "crappy QC in China" but more likely due to something you did during the refitting.
Oddly enough, it is possible for that trigger group's locking in to be so tight that the seer can't get a firm enough grip on the hammer.

"IMHO" ... I would return to just a bit of trimming where the trigger group contacts the stock. My own example required surprisingly little material to be removed. Measure with a depth caliper if you can, then only take off ~a tenth of a mm or so and try fitting it again. If after two or three attempts you still have not fixed the problem, then I'd suggest taking the rifle back to Barney's. If ther's no time for that before you leave to hunt the moose... do you have a Savage in your safe you could use?

If your rifle passes the safety function test, it's unlikely to disfigure you as you've predicted. Otherwise, I would advise against firing it until it will pass the test every time without fail.
 
I was totally unaware of this issue. I thought all bump fires were caused by the firing pin and improperly seated or excessively soft primers.

This issue was brought to my attention as I experienced several slam fires. All happened within 100 rounds of the installations. Never had a bump fire before in the original norinco configuration, but I also never tested for it.

Reason prevailed. I removed more material today. Passes the test every time.

When I get back I will install the new trigger group, and re-bed the trigger area. I will have all the time I want till this time next year to re-assess and make sure all is in order.

The good news is that I fired 4 5-shot groups today. Every one was tight. 1.25" at the largest, .75" at the tightest, all were around the inch size. Will be happy to attempt the MOA challenge upon my return.
 
Thank you to all who replied. Barney as well; your help and expertise is invaluable. Also thanks to those who started and stickied this thread. Definitely a must-read for all who work on this rifle platform.

Thanks again guys!

Alec
 
Just saw this tonight, I have a norc - would have lent you the trigger group - or the entire gun if needed for your hunt.
Glad you got it fixed though, so nice to have so many eyes on a problem when they arise.
This was a good read, have to field strip my gun when my multi-tool gets here, my gun didn't come with one
when I bought it 20 years ago.
Will give this test a go.
 
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