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M14/M1A health check...

This is a discussion on M14/M1A health check... within the Reference forums, part of the M14 M1A Forum category; I've had similar problems w/a loaded model. It was actually a failure to feed problem, all from the left side of the mag.. Sent it ...


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Old October 4th, 2009, 10:32 AM   #16
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Post Failure to Feed from left side if the mag

I've had similar problems w/a loaded model. It was actually a failure to feed problem, all from the left side of the mag.. Sent it off to SAI and they polished the chamber. Still had unreliable feed problems. Removed the op rod spring, installed a mag and fed by hand. What was occurring was that the left bolt lug was contacting the backside, and top, of the bolt stop during each feeding cycle. Enough so that a peen mark was left on the bolt stop in this area. As they left lug moved forward in the rail, it pushed the bolt stop downward. When it did this, the bolt stop bottom pushed the next left side cartridge downward in the mag. This in turn caused enough of a misalignment between the cartridge and chamber, as to cause erratic feeding. Cartridge cases were somewhat deformed through this erratic feeding. If the cartridge is pushed down far enough, the bolt will not catch the cartridge at all. I've measured the thickness of the bolt stop at the top and it was .025 thicker than any of my spare bolt stops. I'm under the impression that the bolt should not contact the bolt stop at all, until the last round is fired. As the bolt stop is a PIA to change out, even with the proper punches, it is awaiting return to SAI this week. Hope you are able to follow my description of the problem. If you have a FTF from the left side of the mag, best to disassemble the rifle and perform the same tests.
dozier

Updated 12/17/09: Well got my rifle back from SAI in November for the above feeding problem. They changed out the bolt stop for one that clears the left bolt lug when it goes onto battery. SAI stated that they fired 80rds out of it at their facility. I checked the finish product, and the bolt does not touch the BS till the last shot is fired. Haven't been able to get to the range till yesterday. Fired 40rds out of two brand new CMI mags. Went thru those rounds w/o a hitch, and no deformed bullets. So if you do have a problem w/your M1A not feeding properly out of the left side of the mag, check for proper clearance on the Bolt Stop. See above post. dozier

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Last edited by dozier; December 17th, 2009 at 04:24 PM.
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Old October 21st, 2009, 05:51 AM   #17
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Just saw another one from another poster...

Gas plug tightness...

The gas plug should be torqued to a minimum of 120 inch pounds (10 foot pounds) to a maximum of 23 foot pounds.

The well accepted range is 120 inch pounds to 150 inch pounds. Put some anti-sieze on your plug when servicing.

If you don't have access to a torque wrench, just German torque it (Good-N-Tight!).

With those torques, the gas plug should not be shooting loose. If you need a torque wrench, go to the local auto store and rent one. You will get all your money back anyway and it will cost nothing. Gas plug torque can affect accuracy, so see what torque works for you.

Once you have a good torque, scribe a line or add some fingernail polish or white out to the gas plug and gas cylinder so that you just have to line up the marks upon service reinstallation.

Keep in mind that as the plug is removed and reinstalled, the plug may have to be tightened a little more than before to achieve the same torque you once had.

Keeping your gas plug torqued will prevent cycling issues.

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Old October 21st, 2009, 09:14 AM   #18
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M14/M1A health check...

This material may have been cover in another of my Posts but this reminder could be helpful.

Last week two gentleman visited bring three M1 Garands they recently received from CMP. All three of these rifles they stated, would not shoot to the degree of accuracy expected. The problem was the same in all three, sight covers. Two of the rear sight covers were worn out, the third would not seat properly in the receiver.

The tension rib on two covers were worn out and the aperture was not being held level in the base, This problem may be the MOST common issue in both the M1 and the M1a/M14's, and the lest common to be checked. Inspect your cover, the tension rib should be well defined. If you are a shooter that uses the elevation knob constantly, the rib wears quicker then expected, even faster if not lubed.

Poor fitting covers are often the result of the retaining slots having grit or dross present, this is more common in cast receivers. Run a small screw driver blade around inside of the slots, you can feel interference, Clean the slots before installing the cover. I like to stone the rounded corners on the cover to insure a complete fit, To make certain the cover fits properly and is flush, install the cover without the rest of the sight, it should sit flush and firm with no tilt, both sides should be inside the retaining wings of the receiver. Use a small amount of lube in the front and rear slots. It is my practice to polish the top of the aperture, often this curved surface has heavy machine ridges. Cast NM apertures have a raised circle on top, the air vent, this bumps the tension rib in some cases, Don't forget to lube the top of the Aperture. A poor cover is similar to worn out motor mounts, nobody wants to know about it. Art

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Old March 24th, 2010, 05:03 AM   #19
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Another addition (torque spec)

If you have a rifle that has a rear-lugged receiver with a torque screw, after seasonal cleaning, be sure to re-torque it from 50 to 55 INCH pounds. I am not sure what the torque should be if you have a double lugged receiver. If anyone knows those torque specs, please feel free to chime in.

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Old March 24th, 2010, 06:42 AM   #20
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Something else on fit of the stock.

If the receiver is loose from front to rear in the stock without the trigger housing in place, it will still cause flyers even if the trigger guard lock up is good.

To test this, take the trigger mech out and turn the rifle upside down with the barreled receiver and stock laying on a bench. Grab the gas cylinder with one hand (and don't touch the stock with that hand) and grab the pistol grip of the stock with the other. Pull your hands apart to see if the receiver will move forward, then push your hands together to see if the receiver will move backwards. On real M14's and G.I. stocks you would see almost no movement because the receiver legs were made so precisely consistant and the stock liners were steel. The steel stock liner took a WHOLE bunch of rounds before recoil loosened it up.

Commericial M14 receiver legs are not nearly so precisely made. Some you have to do a little filing on the stock liner to get them to fit. On others, the receiver legs are too short front to back and that allows the receiver to bounce back and forth in recoil. The only good way to fix that is to epoxy bed the receiver legs or replace the stock.

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Old March 24th, 2010, 09:17 AM   #21
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Originally Posted by tonyben View Post

Gas Port:
It is also a good idea to check the gas port for both obstruction and alignment. If it's plugged, you will be plagued with short stroking or feeding problems.

Pull the op-rod back and lock the bolt to the rear. Tilt the muzzle up until you hear the gas piston slide all the way back. Invert the rifle and lay it in your lap or in a cradle. Insert a 1/16" allen wrench into the hole at the bottom of the gas cylinder. Wiggle it around until you feel it go inside the gas port hole and gently stick it in as far as it will go. BE CAREFUL NOT TO LET THE BOLT STOP DISENGAGE!!! IF SO, THE OP-ROD WILL FLY HOME AND YOU CAN DAMAGE YOUR PISTON AND GAS CYLINDER ASSEMBLY!!! Now that I think about it, it would really stink if your allen wrench sheared and you had half an allen wrench stuck in your barrel. I use a cleaning port to eliminate the risk. You can also throw a block of wood in the action to keep damage from occuring. If you don't want to take that risk, then remove the gas plug and remove your gas piston.
A trick I use to prevent the op-rod and bolt from accidentally being release while doing the above, or even just while I'm cleaning the bore, etc. is to use an empty stripper clip... slide it in with the bolt locked back, then release then bolt so that it's stopped by the clip... it won't budge after that! I had a bolt slam shut on my fingers before, that's when I figured this trick out...

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Old March 24th, 2010, 09:26 AM   #22
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Checks

The best health care check I can think of , other than what has been covered, is the cleaning of the chamber itself. Lots of people think that if they clean the bore, that the rifle is GTG.

Every M14 owner should invest in and have handy,
A Chamber Brush
A Multi-Tool
A Bore Light
A Dental Mirror
Copper Solvent


In addition to this number one pet peeve, the greasing of the op rod spring should not be neglected. Everytime the op rod cycles, it is rubbing and banging around on the springs external surfaces.

Not just gobs of grease, but a very fine film on the outside. I get some on my finger and rub a little all around where the travel of the rod will be. This will get all gummed up from gasses in the op rod hollow and needs cleaning regularly. I use a wooden dowel with a rag around it and some solvent, then Break free CLR and wipe. For those that do not have a hole in the end of the op-rod it will not gum up as fast, but stills needs maintenance.

I helped a guy fix his rifle the other day, and when I looked in the op-rod hollow, I found dried up grass, or what we call in the horse business, Hay,...all wadded up in the far end. Don't ask me how it got there, I have no idea, but his op-rod was filthy inside, and wear marks very prominent on his spring.

Lastly, the care and cleaning of the magazine. Of the last two listed, this is the third number one thing I see neglected. All that grease and gasses get heated up and get in and on the mags. Self explanatory, disassemble and clean and "LIGHTLY "oil the inside and spring, too much oil could cause primer to not detonate from long term storage mags that are kept loaded.

Good Idea Tony ! Good Post Dozier, A new one on me!

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Old July 3rd, 2010, 06:59 PM   #23
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Loose Mag and Failure to Feed

Looking back on it I had several problems with my SOCOM 16. Little by little I resolved them and got it running very nicely but there was one problem that Tonyben has asked me to comment about.

Actually the problem presented itself as several symptoms. The first being that any magazine that I used would fit very loosely in the magazine well, in fact they were so loose that sometimes they would fall out of the rifle while I was shooting. The second symptom was intermittent feeding problems. Sometimes the bolt would not strip a cartridge off the top of the magazine when it would go forward and other times the bolt would jam in to the top of a case and deform it.

I looked things over and I realized that there was something wrong with the op rod spring guide. Early on I noticed that the spring guide would not move. Normally when the bolt is in battery you can reach up in to the mag well and push the spring guide against the op rod spring pressure, mine wouldn't move at all. The part of the guide that protrudes in to the mag well inserts in to the square opening on the front of the magazine and the magazine is held in place by the guide and the op rod spring pressure.

After comparing dimensions against my other rifle, I found that the connector was not in the same location. The one on the SOCOM was about 0.025" or so closer to the body of the receiver (the bottom of the slot that the spring guide sits in).



This created a situation where the op rod spring guide was being pinched between the connector and the bottom of the slot that the guide sits in. This prevented the spring guide from moving far enough in to the mag well and as a result my mags were very loose. To fix the problem I used a hand file to take off a couple of thousandths from the bottom of the slot that the spring guide sits in. The slot on the guide that the connector goes in to is large enough that when I took some metal off the slot the guide had enough clearance to move where it needed to go. I didn't take very much off but I found you had to do this slowly and carefully because just a couple of thousands made a big difference. The original slot appeared to have a slight angle to it and so I attempted to recreate that same angle, and it seems that I was successful because now my mags are nice and tight and I have no malfunctions.

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Old December 16th, 2011, 08:17 AM   #24
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Stock Dimensions and doubling/inadvertent full auto...

I just realized that there was something else missing in this thread...

If the thickness of the stock between the bottom surface of the receiver heel and the top surface of the rear portion of the trigger guard is too far, then the rifle may double or go full auto.

Here are the specs taken from a quote from Gus Fisher:

"....Also, on this stock, the distance between the top of the stock and the two supports for the rear of the trigger housing were too far apart. That causes doubles, triples and even unintentional full auto firing in worst cases. A REAL GOTCHA when glass bedding is to have this measurement off. The G.I. measurement is from 1.700" to 1.725". This stock was well over 1.740" and would have been even worse after glass bedding if I hadn't checked it and glassed the rear of the trigger housing with a little distance between the stock supports and housing. I had to inlet the two supports up a bit to shorten this distance and ENSURE the rear of the trigger housing was down right on top of the supports when I bedded the trigger housing and all came out well.

On a couple of LRB receivers I've glassed, the geometry of the receiver was off so I had to reduce this distance even more so the rifle wouldn't double, triple or go full auto. I had to go down to 1.690" on one and 1.685" on another.

If one doesn't realize this distance can cause functioning problems and is so important to safe operation, this can cause real problems."

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Old July 5th, 2012, 02:51 PM   #25
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Tried to follow Tilt test but the link ends up dead ????

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Old July 5th, 2012, 03:02 PM   #26
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Quote:
Originally Posted by cdngunner View Post
Tried to follow Tilt test but the link ends up dead ????
Here you go...


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Old July 5th, 2012, 05:22 PM   #27
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Most useful thread I've seen on the forum! Thanks guys.

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Old July 5th, 2012, 05:39 PM   #28
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Thanks Tony. Everything I have learned about M1A maintenance I have learned from your material.

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Old December 4th, 2012, 08:12 AM   #29
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Here's a good one I have never seen from Gus in another thread...

Quote:
Originally Posted by Gus Fisher View Post
One HUGE thing many people never think about is oil or grease that gets thrown back between the stock and receiver. The receiver hydroplanes on that just like car tires do it on a road when the rain first starts and the dust/mud makes a slurry until it gets washed off.

If there is oil or grease between the stock and receiver, then it should be wiped off very thoroughly.

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Old December 4th, 2012, 10:41 AM   #30
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I think...

I think tonyben needs an official Thread! Stickeys at the very least! I refer to them all the time it would be great to have instant access!
Great job AGAIN tonyben!!!!

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