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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; Thanks Tony and Gus. You guy's posts make spending hours on this site worthwhile. I probably wouldn't own an M14 (or five) type if not ...


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Old December 4th, 2012, 03:54 PM   #31
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Thanks Tony and Gus. You guy's posts make spending hours on this site worthwhile. I probably wouldn't own an M14 (or five) type if not for this site and the info to be found here!!

Thanks from tonyben and Grateful Lead
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Old March 25th, 2013, 10:03 AM   #32
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Forward mounted scope rail

I just thought of another one I didn't see in the previous posts.

There are some M1A scout owners that experience cycling issues who have the forward barrel-mounted scope rail. This barrel can frequently rub on the operating rod during cycling and interfere with proper function. You can either file some off the rail edges where the impact is happening or just remove the rail entirely.

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Old January 18th, 2014, 11:22 PM   #33
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Well, it's been about a year since anyone dug up this thread from the archives. I figured I'd resurrect it for the new members.

Lots of useful information in this thread by lots of knowledgeable members.

Enjoy!

Tony.

Thanks from TripleTap, Cody M1A and sfoxwell
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Old March 6th, 2014, 05:22 AM   #34
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I just skimmed through this thread again and I didn't see anything about checking for a loose operating rod guide. Although I did mention that the operating rod and the gas cylinder should be aligned, I didn't mention to check that the operating rod guide is tight or not.

Grab the operating rod guide and try to wiggle it from side to side. If there is play, then the operating rod will hit the piston in different locations from shot to shot.

To fix this, have the barrel knurled and re-seat the operating rod guide on the barrel and epoxy it in place. Make sure the op-rod guide is aligned with the gas cylinder and piston tail before the epoxy sets.

Tony.

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Old March 6th, 2014, 06:36 AM   #35
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OK, this is all good information. But it assumes the reader has some of

the basic knowledge to understand what's being talked about.

I'm still new to the M1A, absolutely love it, but get lost in some of the

terminology, abbreviations, etc.

IE: what the heck is a "ferrule"?

Please don't laugh too hard at me, I'm confessing my ignorance in

hopes I can receive some 'gentle' education. I can figure out what's

being talked about most of the time, but that always leaves a little

bit of doubt. Is there a guide for the absolutely M14 ignorant showing

pics of stuff like a ferrule, sight hood, etc. Seems pretty stupid to

the more experienced, but some of us learn better off pictures.

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Old March 8th, 2014, 02:12 PM   #36
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Quote:
Originally Posted by johndm1967 View Post
IE: what the heck is a "ferrule"?
The ferrule is the metal piece at the very front end of the stock.

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Old March 8th, 2014, 02:30 PM   #37
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Quote:
Originally Posted by tonyben View Post
I just skimmed through this thread again and I didn't see anything about checking for a loose operating rod guide. Although I did mention that the operating rod and the gas cylinder should be aligned, I didn't mention to check that the operating rod guide is tight or not.

Grab the operating rod guide and try to wiggle it from side to side. If there is play, then the operating rod will hit the piston in different locations from shot to shot.

To fix this, have the barrel knurled and re-seat the operating rod guide on the barrel and epoxy it in place. Make sure the op-rod guide is aligned with the gas cylinder and piston tail before the epoxy sets.

Tony.
What about the clearance between the op rod guide and the op rod? I'm a machinist and was wondering (and I'm sure this has been either tried or thought of) if a guy could press in a bronze bushing in the guide, polish up the op rod some, and tighten up the clearance between the two. Any real benefit there?

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Old March 16th, 2014, 02:08 PM   #38
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Quote:
Originally Posted by tonyben View Post
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."
Someone asked me to post a picture of where the stock needs to be relieved to remedy this situation.

The surfaces that must be relieved are the areas of the stock where the tang of the trigger group housing contacts the stock. In the picture below, it's the grey bedding area that HAS NOT been routed. The routed cutout is simply to allow the trigger to be pulled. If that cutout is not there, you can't pull the trigger.

Tony.
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Old April 15th, 2014, 05:48 AM   #39
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Here's a couple of new ones....

Action binding after installing a Sadlak NM spring guide

If you've installed a Sadlak NM spring guide and are getting binding when cycling the action, the inner diameter of the operating rod shank may be on the low end of spec (still within, but on the low end). Here's a quote from a member (rifle21) with blueprints...

Quote:
Originally Posted by rifle21 View Post
The inner diameter of the op rod spring passage is shown on the prints as .474 plus .008. In other words the minimum diameter is .474 and the maximum is .482. The spring itself should measure .4575 plus or minus .0025. outer diameter. Hope this helps, and Best wishes to you!
Some M1A owners use a wooden dowel with sand paper wrapped around it and run it inside the shank to open things up a bit.

Gas cylinder fit over the barrel

Even if your gas cylinder is shimmed, there may be some play on the gas cylinder where it fits over the barrel. With the rifle assembled, grab your gas cylinder and try to wiggle it in a rotating manner. If you hear clicking, the barrel can be peened inside one of the spline cutouts to tighten things up. If it's loose, it may or may not effect accuracy.

Tony.

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Old June 15th, 2014, 09:27 PM   #40
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Quote:
Originally Posted by tonyben View Post
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."
Quoting my own post to add pictures...

The sample stock seems to run a little on the short side. Also, it's hard to get an accurate measurement for this, I placed the lower caliper on the contact point and looked over the top of the stock until the upper caliper was even with the top plane of the receiver.

Tony.
Attached Images
File Type: jpg IMG_1786.jpg (1.79 MB, 18 views)
File Type: jpg IMG_1787.jpg (1.81 MB, 16 views)
File Type: jpg IMG_1788.jpg (2.09 MB, 17 views)

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Old October 17th, 2014, 03:07 PM   #41
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Thumbs up Another Vital Safety Tip!!

Here's a golden nugget that our friend, Lazerus2000 sent me via PM. It is good advice for all who see this...

Tony
here in Canuckistan the vast majority of M14 type rifles are the various versions of the Chinese clones. Almost all of the Chinese bolts, irregardless of headspace or lug locking timing issues, have one other potentially dangerous issue.
THE FIRING PIN HOLE IN THE BOLT IS USUALLY OVERSIZE AND THE FIRING PIN TIPS MAY BE UNDERSIZE.

This increased clearance is where brass shavings like to collect, and can cause a very serious safety issue if they impede the free movement of the floating firing pin.

AKA ...KABOOM! From an out of battery primer ignition. This is a REAL concern, and I have seen blocked firing pins more than once.

For this reason, before firing any M14 type rifle, I highly recommend removing the bolt, visually inspecting the bolt face, and shaking the bolt to confirm free movement if the firing pin.
LAZ 1


Tony.

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Old January 1st, 2015, 12:50 PM   #42
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There is some great advice on the M14 on this forum. I have been looking for a gunsmith in Calgary but as luck would have it have not found one yet. For now the videos will have to work for me. Thanks to all you folks for the information, a special thanks to tonyben for his video work. A gunsmith is not a recognized trade in Canada so just about anyone can hang a shingle out, no questions asked. In the United States they have some brilliant gunsmiths because they have the training. Hope Canada jumps on the bandwagon soon and gets this trade certified.

Thanks from tonyben
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Old January 1st, 2015, 02:27 PM   #43
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Originally Posted by tonyben View Post
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.
Tony, I went to the range yesterday and ran 60 rounds though my standard. Could not get consistent groups. It was cold, wet and windy, but still felt good enough about my execution that I started to consider something else might be going on. Was about to start cleaning it and noticed the gas plug was loose. I suppose that's not conducive to function, although I had no cycling issues. Would it also lead to inconsistent POI?

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Old January 1st, 2015, 03:16 PM   #44
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yes it would.

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Old January 1st, 2015, 04:23 PM   #45
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Quote:
Originally Posted by Ric Flair View Post
Tony, I went to the range yesterday and ran 60 rounds though my standard. Could not get consistent groups. It was cold, wet and windy, but still felt good enough about my execution that I started to consider something else might be going on. Was about to start cleaning it and noticed the gas plug was loose. I suppose that's not conducive to function, although I had no cycling issues. Would it also lead to inconsistent POI?
Cdngunner is correct; yes it would effect accuracy and POI. In some rare cases, accuracy gets better because it changes your dwell time. I've seen that happen at least once to a member of this board over the years.

Tony.

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