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Getting frequent double shots

This is a discussion on Getting frequent double shots within the The M14 forums, part of the M14 M1A Forum category; Few things to consider... I remember Art/Shooting Sight mentioning that the removal of material to do the trigger job goes beyond the hardened surface. I ...


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Old March 27th, 2017, 09:53 PM   #31
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Few things to consider...

I remember Art/Shooting Sight mentioning that the removal of material to do the trigger job goes beyond the hardened surface. I don't know if this is true or untrue, but it is something to think about.

The other thing is that the original trigger group was not designed for target shooting, in the NM configuration, or otherwise. My 'loaded' has yet to double fire, but then I'm not running around amidst chaos with people I might not want to shoot accidentally crossing my barrel either. The Job SAI did on it is okay, so far as I can tell, though I also would hardly call it a 'good' trigger compared to others have had my fingers on. When budgets fall into place, I'd really like to try one of Art's jobbies, and see what that's like.

But, my point being, more so that in modifying a battle rifle trigger to fit the needs of a more 'target' application, there is both the fact that you're not starting from the ground up with what you want, but bending what you have to fit a new situation as best you can, it may very well be that it requires some serious care, and that a little variation can result in a lot of variation. I.e., the trigger job I got from SAI might be significantly different than the job done on Badger5th's trigger group, not obviously so, but enough.

I think a SAI 'Loaded' gives a decent amount of value for what you're spending, most of the time. Still, it is not uncommon to hear stories of new owners needing to take advantage of the fantastic warranty relatively early in the relationship.

To be fair we should keep in mind that SAI mass produces these things. Even if you had access to the same parts, you'd not likely get the same finished product from a SAI assembler as you would from their higher priced competition, presumably because much of the increased cost is in attention to detail, in terms of parts selection for fit, assembly, finishing, tuning, and even a trigger job.

You pay less, you might get lucky, or you might need to use the outstanding warranty.

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Old March 28th, 2017, 07:54 AM   #32
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Very well stated. I would add that despite Springfield's very good warranty service, they no longer use the higher-quality GI parts I want in my rifles in some cases, such as the trigger group components and bolt components that are most critical. To me, it is worth it to spend $20 on a GI trigger/sear and $39 on a GI hammer, and install them myself in minutes, than to risk shipping around an $1800+ bedded rifle, do without it for an uncertain period of days or weeks, risk damage or loss in return shipping, and get back a gun still with SAI parts in it, that I would replace down the road anyway. I limit these comments to basic, easy-to replace, cost-effective items that you might as well upgrade yourself. For more critical fails such as a bad barrel, bolt problems, stock fitment issues, etc etc, she'd have to go back. The trigger group parts are easy to change, and try out, and are also easily reversible if you need or want to later on.

I will say that while I really don't care for the so-called Nat Match trigger work on SAI rifles, I do think the medium barrel and the very decent bedding job on my particular Nat Match were worth the extra price of admission. It is already showing itself to be a superbly accurate rifle that was well-assembled and properly clearanced in all other respects than the sad trigger job, which had heavy take-up, grit, some creep, and had too light of a break. I'm not sure how that qualifies for Nat Match, but it's what I got. The stock trigger on my Scout Squad was better, surprisingly. Maybe I got a Friday NM trigger job and someone just filed the sear down a bit until the trigger broke at about 4 lbs or less, and they threw it in the gun and called it good LOL! I suspect that when I go pull out and inspect the SAI parts I will find some sketchy angles and filing/polishing work I am not a fan of.....

I'm not sure because I made my trigger group upgrades all at once, but I suspect the Tubbs hammer spring alone may have been worth the time and effort upgrading the trigger group parts! Feels pretty good!


Last edited by MGSchindel; March 28th, 2017 at 06:36 PM.
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Old March 29th, 2017, 05:43 AM   #33
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Originally Posted by MuppetMeat4Me View Post
I remember Art/Shooting Sight mentioning that the removal of material to do the trigger job goes beyond the hardened surface.
Just to clarify, I don't think it is a given that a trigger job always goes beyond the case hard layer, but it is certainly a big possibility.

USGI spec on the hammer is a case hard layer of 0.012 to 0.015 thick. For perspective, a piece of paper is about 0.003 to 0.004 thick, so we are talking a hard layer that is about 4 sheets of paper thick.

If all you are doing is polishing surfaces, you will likely not go through the case layer, but if you are shortening up the hooks on the hammer, it's not certain, but I think the chances are pretty good that you are.

For perspective, low carbon steel is pretty flexible, high carbon steel is harder, so it has great wear resistance, but it is brittle. Think of a hard boiled egg with a shell. The shell gives wear resistance, even though the egg remains flexible. The way you make a 'hard boiled egg' in steel is to make the part out of low carbon steel, and when you are done, you pack the part into carbon powder, and put it into a furnace. You heat it past red hot - not to melting, but hot enough that some of the carbon powder begins to dissolve into the surface of the part. The temperature and time you hold it there determines how far the carbon soaks in.

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Old March 29th, 2017, 04:57 PM   #34
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After seeing even more web posts about SAI rifles with NM trigger jobs firing doubles, I went back and reinstalled my SAI "NM Job" hammer and trigger parts to see what was going on. I believe there is definitely something not kosher with my SAI "NM trigger job" parts. The take-up is heavy and a bit gritty (stock spring?), and at the very end of it, there is a perceptible stage of extra stacking, followed by a very odd, wobbly creep, almost like a mini "thunk" that is also audible as a "click". After that, even the slightest movement will set off what I can only describe as a "hair trigger" that feels like it is about 2 lbs or less. Not sure if I'm describing this process right. But it really reminds me of an old Colt pre-gold cup 1911 pistol I had bought used, that a rookie gunsmith had at some point butchered a trigger job on, messing up the hammer and sear relationship.

I'll pull it back apart and take a closer look at the sear and hammer engagement surfaces tomorrow in better light, before chucking that crap back in the ziplock baggie. If that's a proper SAI-style competition trigger, which I can't imagine, I'll live without it. With the USGI hammer and trigger/sear installed in that rifle, there is no weird creep, clicking, or hair trigger after-effect, just a smooth take-up, gradual staging and a clean smooth sudden release of the hammer. No hitches, glitches, funky clicks....and NO DOUBLES. Nor did my groups open up and get worse with the USGI trigger parts, after I had installed them in that rifle to cure the doubling problem. Thank you, Uncle Sam!

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Old March 30th, 2017, 05:04 PM   #35
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Grateful for all the feedback for my OP.

I will be going to a local gun show tomorrow and will be doing some shopping for spare parts. Would like to get a GI hammer, sear, and trigger for my naughty lil' double shooter.

First question, My understanding is that the M1 trigger group is identical to the M1A/M14 trigger group. True or False?

Second, Is there a way to distinguish GI parts from SAI recent made parts?

Finally, any other (reasonably cheap) backup parts that I should keep an eye out for while I am there?

Regards,
Badger

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Old April 1st, 2017, 07:47 AM   #36
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I can only tell you that the internet is your friend, and there are several very fairly priced vendors with great reputations, and on-line stores, that still have and sell actual NOS or excellent+ reparkerized USGI parts. I have heard of faked parts, or some shops selling commercial parts as USGI NOS. The genuine NOS trigger/sears and hammers I've acquired from some trusted sources, and used in all three of my newer SAI rifles, along with the spares I've scooped up for a rainy day, were mostly M1 Garand parts, and ARE interchangeable for SAI semi-auto guns. For example, places like treeline and fulton sell NOS garand trigger/sear for $21! Hammers are often between $35 and $70 when available. A tubbs hammer spring and some nice hard NOS USGI hammer and trigger pins is about $13 for a little kit. This is a small investment for vintage hardened-steel M1A trigger parts, for a commercial rifle that can cost you from $1200 to $1900 brand new depending on the model!!! While you're at it, spare REAL USGI firing pins, extractors, ejectors, and their associated springs, are a very good idea! All those are critical contact parts with limited lives, especially the bolt guts, and the necessary spares are a for-certain eventuality....

If you cannot source locally, or are unsure of the source or legitimacy of the parts, you can try some trusted online M1A vendors....while they still have these parts for sale! If it was not for the fine folks at Treeline and Fulton, my Socom would still be living in a plastic stock, not extracting spend casings reliably, and shooting horrid 7" groups. And my National Match would still be shooting doubles. Cheers and happy parts hunting, it's part of the M1A tuning and upgrade fun!!!!

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Last edited by MGSchindel; April 1st, 2017 at 07:40 PM.
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Old April 1st, 2017, 07:25 PM   #37
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I got a chance to inspect my SAI NM trigger group parts, and found a few issues. Perhaps more than expected. But I've certainly paid for the education.

The upper deflection surface of the SAI sear is ground down crookedly and excessively, like a 15-year old with half a clue took a dremel to it. No I am not exaggerating.

The SAI hammer hooks are rough, crooked, curved, as they have been kissed more than once with some sort of dremel or grinder, and the resulting surfaces are crooked, uneven, and at a questionable angle.

The inept trigger job is what caused the glitches and excessively light trigger break. If these SAi cast parts ever WERE hardened properly, such heavy grinding surely took off any hardened layer anyway. The parts are junked.

But more interesting, I believe the bedding in my SAI Nat Match is excessive, and crooked, under the trigger housing tabs where they meet the bottom of the stock. The trigger group fits very tightly in this rifle as would be expected with a bedded NM rifle. But it appears the folks at the factory then also forced the trigger guard closed WAY too aggressively after the excessive trigger group bedding job. Upon inspecting the SAI trigger guard, I noticed a galled and flat-spotted area on the underside of the soft SAI trigger guard's locking lug on just one side, where it contacts the receiver. That led me to inspect the SAI cast receiver where the trigger guard lugs lock into the receiver. And I found that the upper edge of the locking notch in the soft metal receiver on one side is crushed down and pressed inward, causing a sharp edge of pressed and deformed steel to protrude inward. This, combined with the excessive bedding material under the trigger guard along the bottom of the stock, has led to the trigger guard possibly sitting lower in the stock than might be ideal. Fortunately the USGI trigger guard I installed in lieu of the SAi trigger guard when i changed the hammer and trigger to USGI, fits less tightly and does not lock down so insanely.

I then came across this bit of information on bedded actions and double fires..... "When too much bedding material is added between the stock and trigger housing pads, it can lower the trigger housing too much for the bolt to properly reset the hammer and you could wind up with unintentional double firings from one pull of the trigger....."

With my particular Nat Match rifle, I now believe my random doubles may have been caused by varying contributions from a combination of all or any of the following... 1) a horrid, hack trigger job that buggered the factory SAI hammer hooks, causing weak sear retention, 2) an excessive, crooked bedding job under the trigger group, and 3) the ridiculous use of excessive force to close the SAI trigger group into the bedded stock after the fact, causing the soft SAI trigger guard and soft SAI receiver locking notches to be squashed and mangled a bit, causing the trigger group to sit borderline low in the stock in conjunction with the excessive bedding under the trigger housing tabs.

I'll be honest that at this point, this is the third SAI rifle in the last year and a half that I've had to gut and replace most everything with mostly all USGI parts, in order to rectify significant function and durability issues, and I'll not be buying another commercial SAI rifle again, based on what I now know and have experienced.....The warranty doesn't help because I don't want the same folks working on the rifle when I can do a better job myself, and I also don't want the SAI commercial metal parts they'd simply send it back with. The SAi commercial metal is just too SOFT for my liking, and the overall SAi factory assembly work on these rifles is nowadays just simply below what I find acceptable. The good news is, most of it has been able to be rectified. All three rifles are now running great, with terrific accuracy and no more function issues, thanks to USGI parts (and a lot of my time and elbow grease, and knowledge derived from this awesome forum, to put things right).


Last edited by MGSchindel; April 4th, 2017 at 04:50 PM.
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Old April 2nd, 2017, 07:06 AM   #38
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Here's the horrid SAI hammer from my "SAI hand-tuned" Nat Match trigger group, so you get the idea of what sort of "smithing" you are paying extra for. This is a brand new 2017 NM gun, straight from SAI:

The hammer hooks, very hard to see what's really going on in this pic, but the right outer hook is WAY more ground away than the left. It is clear that the hacker used some sort of curved grinding wheel, looks like maybe a dremel was used freehand, making deep, curved grinds into the hammer hook surfaces, and he came back to make multiple cuts and passes, from three or four different angles, trying to "freehand" things to look a bit more "equal" after each sloppy pass. The leading lower inside edge of the left hammer hook is cut in the wrong direction, and the upper side of that hammer hook is nearly cut away entirely, on a curve. Both inside and outside hammer hooks have had their opposing inside and outside corners "shaved" and the hooks, instead of being flat and even, all have a sort of tee-pee shape that peaks in the middle. The pic with its overexposed lighting looks much less horrific than the hammer itself actually is, in person. The inside hooks you cannot see from this angle are nearly rounded off. The cut surfaces are also plagued with notches, like someone then passed over them with a rough file perpendicular to the "polishing jobs", and left vertical scratches all over the uneven surfaces of both forward and rear hooks. I'm surprised I wasn't getting more blatant function fails right from the first rounds fired. Apparently this is a great factory mod if you want a hammer for firing double-fire bursts....Class 3 hammer?? LOL!



I don't want to pull the NM apart again just to take more pics, due to the fact that it is bedded, but the bedding job around the trigger, and the soft deformed commercial SAI trigger guard tabs, are worse that the "custom shop smithing job" on the trigger internals.

Oh, here's some more magical smithing, on the NM trigger/sear. Clearly the same round grinding wheel dremeling was applied liberally, freehand, to the upper hammer deflection surface of the sear pivot assembly.....A nice, deep concave rut ground into that surface, the exposed, uneven, concave portion of which is now soft as butter, ground right through any hardened surface, as can be seen from the deep gouges already left in it by the back hammer hooks kissing past it, at only 200 rounds on the gun......



In the end, a $20 NOS USGI trigger/sear, a beautiful $30 HRA hammer I lightly stoned the hooks on myself, a tubbs hammer spring, a USGI trigger guard, and a few other little goodies, totally transformed this gun, and stopped the doubles and functioning issues dead in their tracks. I had to lightly remove some of the bedding material from under the trigger group tabs, too, to bring the trigger group up in the stock slightly, where it belongs. Things are playing nicely together with the USGI trigger guard in place, holding it all together tightly. And the sadlak guide rod, upgraded op rod spring and TiN gas piston I installed cut groups down noticeably smaller and made the cycling smoother. I'm getting less than 1moa at the range right now with the rifle's favorite load, so I can't complain about the current fitment and accuracy! It's just a shame I had to correct most of what the custom shop "did" to make the gun "NM", and that I had to gut the rifle and rebuild it with USGI and sadlak parts to get there LOL! It has not been a cheap or easy lesson, but lesson learned for certain, and I've learned a TON about how to make these rifles run and shoot. I'll probably replace the soft SAI op rod at some point too, as soon as I see the roller wheel recess starting to peen and deform....And then she'll be GTG for the long haul!

I do continue to be impressed by the excellent medium barrel that SAI installed on this gun, and the job they did installing it and the bolt, getting everything in spec. Credit where credit is due! I believe that SAi gets the barrels as blanks and finishes them out?

Cheers!


Last edited by MGSchindel; April 4th, 2017 at 04:47 PM.
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Old April 17th, 2017, 11:33 AM   #39
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Quote:
Originally Posted by MGSchindel View Post
Oh, here's some more magical smithing, on the NM trigger/sear. Clearly the same round grinding wheel dremeling was applied liberally, freehand, to the upper hammer deflection surface of the sear pivot assembly.....A nice, deep concave rut ground into that surface, the exposed, uneven, concave portion of which is now soft as butter, ground right through any hardened surface, as can be seen from the deep gouges already left in it by the back hammer hooks kissing past it, at only 200 rounds on the gun......

I don't think the part of the sear you're pointing out contacts the hammer hooks.

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Old April 17th, 2017, 11:43 AM   #40
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wondering why shooting sight isn't installing a link to his triggers during this conversation?
http://shop.shootingsight.com/

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Old April 17th, 2017, 01:15 PM   #41
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The reason the sear has that uneven area is that they simply take a file and cut the hammer hooks using the sear as a rest while filing. It results in hammer hooks that are filed flat which puts a sharp edge on the first contact area as the hammer is cocked and engages the sear. This in turn causes early wear on the hooks and sear face which can result in early failure to maintain the required 4.5 pounds of pull - not to mention doubling.

It's an expedient way of adjusting the trigger and reducing second stage creep, but a very poor way to do it. Armorers who know what they are doing are careful to maintain the radius on the hooks while stoning. A proper trigger job will last thousands of rounds and give very consistent results.

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