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JMason5067

Troubleshooting time.

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Just got done test firing my PA-10 after installing a Superlative arms adjustable gas block, correct length (12.06 inch) gas tube, and a JP enterprises carbine length polished recoil spring.

The gun ran fine unmodified, replaced the H2 buffer with an H3, and it ran fine. I replaced the gas tube, block, and drive spring at the same time, and began the gas block adjustment process with the gas turned all the way off, as expected the bolt didn't move, went through the process of one turn out, and fire until it started ejecting the spent case, but the bolt wouldn't lock back, or strip another round out of the magazine. That is where progress stopped, the adjustment screw is turned all the way out, and it will eject the spend case, but will not feed or lock back.

Where did I go wrong with this? It seemed pretty straightforward, but I seem to have run inti an if it's not broke, don't fix it moment. Anyone have any suggestions on getting this thing running again???

 

                        Thanks in advance Gentlemen.

 

 

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Id swap back to the original block and verify function just to be sure as a first step. 

 

Any particular reason you went to the new parts? You said gun was running fine in original configuration? 

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Are you sure the new gas block is where it needs to be? The old gas block worked maybe put it back on. My PA10 runs fine without an adjustable gas block.

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1 hour ago, Armed Eye Doc said:

First thing before changing anything, will the bolt hold open if you manually pull the bolt open with an empty mag? 

Yes Sir, it ran before I started messing with things.

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4 hours ago, JMason5067 said:

Just got done test firing my PA-10 after installing a Superlative arms adjustable gas block, correct length (12.06 inch) gas tube, and a JP enterprises carbine length polished recoil spring.

The gun ran fine unmodified, replaced the H2 buffer with an H3, and it ran fine. I replaced the gas tube, block, and drive spring at the same time, and began the gas block adjustment process with the gas turned all the way off, as expected the bolt didn't move, went through the process of one turn out, and fire until it started ejecting the spent case, but the bolt wouldn't lock back, or strip another round out of the magazine. That is where progress stopped, the adjustment screw is turned all the way out, and it will eject the spend case, but will not feed or lock back.

Where did I go wrong with this? It seemed pretty straightforward, but I seem to have run inti an if it's not broke, don't fix it moment. Anyone have any suggestions on getting this thing running again???

 

                        Thanks in advance Gentlemen.

 

 

The gas port is too small. Period.  Time for the drill bit. 

What's the configuration of the barrel, i.e., 18" midlength gas, whatever. I already know it's midlength gas, based on the gas tube you used. What's the barrel length?  I'll tell you what the gas port diameter should be (range from min to max).

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2 hours ago, blue109 said:

Id swap back to the original block and verify function just to be sure as a first step. 

 

Any particular reason you went to the new parts? You said gun was running fine in original configuration? 

I had read that the gun was over gassed, in the interest of keeping the guts clean, I replaced the gas block. I at times am the master of messing with what doesn't need fixed.

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7 minutes ago, 98Z5V said:

The gas port is too small. Period.  Time for the drill bit. 

What's the configuration of the barrel, i.e., 18" midlength gas, whatever. I already know it's midlength gas, based on the gas tube you used. What's the barrel length?  I'll tell you what the gas port diameter should be (range from min to max).

Wouldn't it still run if the gas block was set to run wide open? What is involved in drilling the gas port? It's an 18 inch barrel, and thanks for your input 98Z5V

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3 minutes ago, JMason5067 said:

I had read that the gun was over gassed, in the interest of keeping the guts clean, I replaced the gas block. I at times am the master of messing with what doesn't need fixed.

IF it's the 18" barrel with the 0.750" gas block diameter, it was never overgassed.  The gasport will be 0.070" on that particular 18"barrel, and it's too small.  It needs to be 0.080"~0.085", for that 18" config. 

It was never overgassed - it was under-recoiled, straight from the factory.  Buffer weight too light, spring too weak, right from them.  "Not enough ASS to control the MASS."  Not enough buffer weight nor spring pressure to control the mass of a .308AR BCG and the pressure of a .308 Win round. 

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We replied at almost the same time. Well, if your gas block is wide open, and it's not working, the only other thing that can constrict gas flow is- gas port diameter.  Too small.

Since you already have the adjustable gas block - and a good one- here's what I would do, if it were mine.  You need a range of 0.080"~0.085" for that barrel config to run properly.  Maximize use of the adjustable gas block that you already have.  If it was mine, I'd drill it to 0.090" and dial the block down to function properly.

Edited by 98Z5V

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Id put it all back to factory like when it was working. Id buy some crappy milsurp ammo and some expensive stuff. Id shoot a mag of each and if they both functioned id stop changing parts and enjoy my rifle. 

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5 hours ago, JMason5067 said:

The gun ran fine unmodified, replaced the H2 buffer with an H3, and it ran fine. I replaced the gas tube, block, and drive spring at the same time, and began the gas block adjustment process with the gas turned all the way off,

Recoil system has been changed, completely.

Before, it "felt over-gassed" because it was under-recoiled.  Too small of a gas port, at(probably) 0.070", so "over-gassed" isn't an accurate description, and not even possible with a gas port that's too small. Under-recoiled is a very accurate description, and why it felt harsh to shoot.

Now that the recoil system is up to snuff, it won't cycle fully, because that gas sport is still too small... 

Drill time, 1/4" wooden dowel down the barrel when drilling...

Edited by 98Z5V

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The too-small gas port in the barrel is the "band-aid" used in order to run a cheaper $$$ recoil system, that will probably work for most of the people, most of the time, with most of the cheap ammo out there - even though it feels harsh. An inexpensive gun has to cut corners somewhere,to appeal to the masses.  7 5/8" internal depth receiver extension, the extra tungsten in 3.250" H3 buffers, and a more expensive, proper, .308AR recoil spring cost more money.  It's easier to use AR15 parts that you already make, recoil spring included.  To make it run like that, not beat up parts and destroy shoulders, your "band-aid" and compromise is making the gas port too small.  Restrict gas the cheap way.

Most people mis-diagnose this thing, and say it's "over-gassed" and just add an adjustable gas block. So, how is it over-gassed, when the gas port diameter isn't even near what should be in that barrel config?...   It's not over-gassed - it's under-recoiled, based on money. 

Everything about those guns is money-driven, and doesn't follow the design or operational characteristics of the original platform at all.  It's all about money, and making the cheapest product that you can, from decent materials.  The materials are good - the execution of the "making of the gun" is all about the bottom line, and an inexpensive product. 

Edited by 98Z5V

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8 minutes ago, JMason5067 said:

.080 is the gas port diameter I am shooting for, yes? 

Certainly not the expert by any stretch, but I believe yes, that should be the minimum if all else is proper with recoil and gas. Fwiw, that's where I'm starting on mine once my recoil/gas parts start trickling in.

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Just now, Peachey said:

 

Certainly not the expert by any stretch, but I believe yes, that should be the minimum if all else is proper with recoil and gas. Fwiw, that's where I'm starting on mine once my recoil/gas parts start trickling in.

Good to know, thanks. My recoil system is done, 2.5 inch H3 buffer, 7 inch depth receiver extension, and JP Enterprises spring. Hoping the larger gas port gets this thing running again.

 

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7 minutes ago, JMason5067 said:

Good to know, thanks. My recoil system is done, 2.5 inch H3 buffer, 7 inch depth receiver extension, and JP Enterprises spring. Hoping the larger gas port gets this thing running again.

 

I reread up the thread again, 98 suggested .090 since you have the adjustable gas block. I'd go by his advice. So I hate to add confusion, but maybe go .090 and back it down with the gas block as needed?!? It makes sense in my mind anyway.

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1 hour ago, blue109 said:

If only there were a way to get the gun to run without all these modifications......

 

If there was only a platform or pattern to follow, so manufacturers could get this shiit right, as they send it out...  Right?...

3 major platforms, multiple spin-offs with their own take on it...  fuktard companies that think AR15 recoil springs are the same thing as the EA1095 spring...   buffer weights all over the place...  

There's a platform to follow for proper function, and it's pretty damn easy.  If your recoil system and gas system are balanced, as they should be, and you have enough "ass for the mass" in the recoil system in the first place, then it's super easy...   Stick with Armalite recoil system specs (Eugene Stoner made the thing, and it worked then), and stick with a proper gas system (barrel gas port position, tube length, gas port diameter).  The gun will run, all day long.

Deviate from that, "do what you want to do" as some parts manufacturer or budget gun builder- and the gun doesn't run like it was designed to run.

We've seen this for 10 years now on this board - and try to fix it every time, based on what someone "thinks" is going on...    We've seen it all, literally... 

Edited by 98Z5V

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4 hours ago, JMason5067 said:

Good to know, thanks. My recoil system is done, 2.5 inch H3 buffer, 7 inch depth receiver extension, and JP Enterprises spring. Hoping the larger gas port gets this thing running again.

 

What's that 2.5" H3 buffer?  List it.  H3 is 5.4oz, and that's the proper weight - but it's not commonly attainable with 2.5" of buffer.  What's the spec on that JP spring?

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Was there not a member here that tried this adj. GB out & the design would not let enough Gas to properly cycle the 308 ? I think it was jtallen83 ?

I have a SA Gas Piston system in an 5.56 & the adj. works fine . I also don't think it reads on their web Sight , that the adj. gas Block or bleed off type GB , is only for AR 15.

I would call them .

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13 hours ago, 98Z5V said:

If there was only a platform or pattern to follow, so manufacturers could get this shiit right, as they send it out...  Right?...

 

I know man, im just being difficult. I know we all like to lego up our lego guns, but when you have something that works, and throw parts at it just for the sake of throwing parts at it that will only marginally improve its operation under the best circumstances,  you might be better off just going back to the known good until you have a strong grasp on these beasts and know exactly what it is you are trying to accomplish and how you plan to accomplish it. 

 

Ive reverted pretty hard back to KISS on almost all my guns and I might jus be salty so feel free to tell me to shove it lol. 

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1 hour ago, blue109 said:

 

 

Ive reverted pretty hard back to KISS on almost all my guns and I might jus be salty so feel free to tell me to shove it lol. 

Everytime I think I have this figured out, I go and fix something that doesn't need it. Learned the lesson again.

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