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Short stroking.

This is a discussion on Short stroking. within the The M14 forums, part of the M14 M1A Forum category; I took my two newest builds out to sight them in. Builds are JRA receiver, with Sarco/Citadel barrel, and a GWLA receiver with SAI Medium ...


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Old May 21st, 2020, 03:54 PM   #1
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Short stroking.

I took my two newest builds out to sight them in. Builds are JRA receiver, with Sarco/Citadel barrel, and a GWLA receiver with SAI Medium weight barrel.
JRA M14 ran like a top with MK316 spec ammo(my reloads).
The GWLA M14 short stroked every other round. Ejected empty, cocked the hammer, but failed to pick up a new round. When it did chamber, the rounds were not "stuck" in the chamber, because the bolt opened easily with a round in it. Ejection seemed a little sluggish.
MK316 specs are a nominal 41.7 gr of IMR4064. When I went to some hotter loaded ammo, 42.2 gr, it was a little more consistent. Only short stroked about every 3rd or 4th round.
I went over the rifle when I got home. Passes tilt test in the stock, and out of the stock. Rifle is well lubed. USGI refinished trigger group. Hammer might be a little harder to cock than my other one. Difficult to tell. Gas port lined up properly. Tested with a #48 drill bit.
This is an SAI barrel, so it might be a bit rough. Though I think I had worked it over years ago.
I guess I will load some ammo a little hotter(go up another .5 gr) before I go out next week, and see if that works. Until everything gets broken in.

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Old May 21st, 2020, 04:09 PM   #2
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Mine needed 200/300rds to start working like I wanted it to

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Old May 21st, 2020, 04:14 PM   #3
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Mine needed 200/300rds to start working like I wanted it to
Thanks, Jeff. Good to know. I've had this barrel for years, but it's probably only got 60-70 rounds through it.

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Old May 21st, 2020, 04:25 PM   #4
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Make sure the gas port isn't partially blocked.

A quick check is to look at the barrel, just in front of the gas lock. You should see at least one complete thread.

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Old May 21st, 2020, 04:27 PM   #5
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I wouldn't think the barrel had anything to do with short stroking, unless a chamber issue. Sounds like something else, but those with more smarts than me may have other ideas. Really shouldn't need any break in time.

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Old May 21st, 2020, 05:10 PM   #6
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I feel you pain. Took more time to convince the one GWLA I have to run than any other rifle I own. Safety bridge had sharp edges and it would lock the firing pin up so it didn't want to cycle reliably. A little polishing took care of that. Also, the width between left and right lug recesses was too tight. Got it to function with a well worn Winchester USGI bolt after some fitting using dykem and abrasives, a bit of work and nasty words it is satisfactory, finally, with a TRW bolt I had wanted to use initially.
GWLAs , that I have seen, were nicely finished on the exterior so they were pretty, but working areas that count left much to be desired.

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Old May 21st, 2020, 05:13 PM   #7
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Took more time to convince the one GWLA I have to run than any other rifle I own. Safety bridge had sharp edges and it would lock the firing pin up so it didn't want to cycle reliably. A little polishing took care of that. Also, the width between left and right lug recesses was too tight. Got it to function with a well worn Winchester USGI bolt after some fitting using dykem and abrasives, a bit of work and nasty words it is satisfactory, finally, with a TRW bolt I had wanted to use initially.
GWLAs , that I have seen, were nicely finished on the exterior so they were pretty, but working areas that count left much to be desired.
Well, this is a late GWLA receiver and a TRW bolt. So, that might be part of the issue. I've been expecting to have to do a little work on it.

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Old May 21st, 2020, 07:53 PM   #8
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Might I suggest installing a Schuster adjustable gas plug and dial it up or down until your rifle is working correctly? In this case, you can close the plug slightly and trap more gas until the rifle performs all the functions that a semi-auto should.
Hope this might help.
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Old May 21st, 2020, 08:32 PM   #9
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Keep shooting and let it polish itself

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Old May 22nd, 2020, 02:32 AM   #10
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Quote:
Originally Posted by Sailormilan2 View Post
Well, this is a late GWLA receiver and a TRW bolt. So, that might be part of the issue. I've been expecting to have to do a little work on it.
Be patient with the GWLA. Like Jeff says shoot the heck out of it and it should work better. Too bad they weren't around long enough to get things right.

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Old May 22nd, 2020, 03:41 AM   #11
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On GWLA I've seen, the left lugway in the receiver needed a bit of gentle massaging to get bolt to open/close smoothly. It is between the point where bolt is locked and the cam radius. This little hiccup may just be the hesitation that is causing your problem

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Old May 22nd, 2020, 06:49 AM   #12
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How about trying some factory loaded M80 or FGMM ammo . Might not have anything to do with the Rifle mechanically . MY GWLA is smooth as silk .

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Old May 22nd, 2020, 07:00 AM   #13
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Well, I did two fixes last night. I took nf1e's advice re lapping, and lapped the left lug raceway using a Polytech bolt. Polytech bolt lug is a bit thicker, top to bottom, than the TRW bolt I was using. It seems a bit smoother now.
The second fix was the cylinder lock. KurtC said to check and make sure that there was at least one complete thread above the lock. I had had issues when putting everything together with the lock not timing "correctly". It clocked to about the 4 o'clock position, and I was always told to not force it. Reversing the lock didn't help things, so I had backed it off. Apparently too far, since there were no threads above the lock.
Anyway, I tapped the gas cylinder down a bit to allow some room, and gently tapped the lock into the proper 6 o'clock position. Now, I have about 1 thread above the lock.
Testing will tell if I really fixed it.

One another note, every time I work on one of these I learn things. While checking the bolts out, I discovered small differences in the bolt by manufacturer. I have two TRW bolts(one is no good) and 2 Chinese bolts, 1 HRT bolt (on a rifle, not taking it off to check), and 3 Win bolts(one off so it can be checked).
These Chinese bolts have the thickest left lugs, and are smooth on the bottom of the left lug. The one Win bolt I check had the thinnest left lug, and was smooth on the bottom. The TRW bolts were both thicker than the Win bolts, but that added thickness appeared to be caused by a small "pad" forged into the bottom of the TRW left lug. Pad was only on the front bottom of the lug.
When I take my HRA rifle apart I will check it's bolt and see how it is.

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Last edited by Sailormilan2; May 22nd, 2020 at 02:09 PM.
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Old May 23rd, 2020, 10:13 AM   #14
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Guys there is absolutely nothing wrong with the GunWorks of Lower Alabama receivers, I have four, two of which have been built into excellent M14 rifles. Both rifles, a XM25 and a all major parts TRW build were built by Jon Wolfe and JD. No special anything had to be done to bring these receivers into spec. absolutely nothing. I stayed in constant contact with them throughout the build process and they never mentioned any concerns, again absolutely nothing.

There is only one person I am aware of that has had issues with a GunWorks receiver, and I believe it stems more from who made it then what was made.

So when reading some of these post, please bear in mind who is doing the writing.

Like I said, I have shot the two I have had built and they shoot lights out! They cycle smooth as silk and not one hiccup, never.


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Last edited by XM25Ren; May 24th, 2020 at 02:46 PM.
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Old May 23rd, 2020, 10:27 AM   #15
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Quote:
Originally Posted by Sailormilan2 View Post
The second fix was the cylinder lock. KurtC said to check and make sure that there was at least one complete thread above the lock. I had had issues when putting everything together with the lock not timing "correctly". It clocked to about the 4 o'clock position, and I was always told to not force it. Reversing the lock didn't help things, so I had backed it off. Apparently too far, since there were no threads above the lock.
Anyway, I tapped the gas cylinder down a bit to allow some room, and gently tapped the lock into the proper 6 o'clock position. Now, I have about 1 thread above the lock.
Testing will tell if I really fixed it.
The best way to install a gas cylinder is to tap the cylinder and front band all the way against the barrel shoulder. Install the lock as far as it will go. It will usually stop at about 10'clock.

Back the lock off to 6 o'clock. Tap the gas cylinder forward, tight against the lock. Install the piston and plug, tighten to 15 ft lbs.

After test firing, you can worry about timing, shims and all that other voodoo.

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