AR-10 .308 malfunction, double feed and damaged casings

[JohnnyA1970]

PSA model .308 will fire a few rounds without malfunction, then double feed, obviously damaging the rounds. Prior to malfunction, the brass is ejecting a considerable distance at approximately 1 to 2 o'clock. Also, there were brass shavings around the extractor where it has been ripping off a small piece of the cartridge base. Factory Hornady ammo, no gun show re-loads, mags appear to be ok....where should I start? Heavier buffer and new spring? AGB? Trying to hit the nail on the head the first try so I'm open to any and all advice. Photos of casing base as well as rounds damaged by double feed are attached. Thank you.

 

[Makinchips208]

Pic or better description of exactly how the malfunction is when it stops? Is the empty case still in? Is the bolt riding on top of these damaged cases? Etc.
But if it is new, before I changed any parts, I would start with different mag and or different ammo.

 

[JohnnyA1970]

I'll shoot it again tomorrow and take a pic of the malfunction and post to the thread.

 

[JohnnyA1970]

I will shoot it again after work tomorrow and take a pic of the actual malfunction, will post to thread.

 

[SupressYourself]

What gas length? Shooting suppressed?
From you ejection description, it sounds severely over gassed. Your case heads also indicate early unlocking, usually due to too much gas.
AGB and heavy buffer would help.

 

[whatsupdoc]

If that is factory ammo something is very wrong the primers are leaking.
Is this a factory gun? barrel length ? gas system length? AGB?

 

[BCP]

Looks like hot ammo. Try different stuff like some basic FMJ loads.

 

[jMarine]

Definitely need to slow the carrier down. Go with what @SupressYourself suggested.

 

[mtrmn]

The following recommendations assume your gun is bone-stock PSA without modifications.

IF YOU HAVE THE ADJUSTABLE CARBINE STOCK start here:

Armalite AR 10 6 POS Receiver EXT. Kit AR10REKIT01

Armalite AR 10 6 POS Receiver EXT. Kit AR10REKIT01 Sale! Call (570) 368-3920 or visit EuroOptic.com

www.eurooptic.com

This will get you over to the longer buffer tube that will use std length carbine buffers. The tube is 7-5/8" deep internally. The buffer will be 3-1/4" long and it will weigh 5.4 oz. That's H3 weight in AR15 terms. This is the basic starting point for a 308 to handle the recoil of the larger round.

The buffer tube you have will only be 7" deep internally and the buffer itself will be 2.5" long and will only weigh ~3 to 3.8 oz. at the most in a stock PSA 308. This is totally inadequate for 308 IMO as it allows the bolt to unlock too soon and travel too fast. The above kit will assure that your recoil system will be designed from the ground up for a 308, and all the parts are designed to work together. Don't attempt to mix/match parts between the 2 recoil systems, they will not work.

Also-unload the gun, lock the BCG to the rear, and turn it upside down. Looking through the magwell see where the end of the gas tube is. It should terminate at the halfway point of the cutout for the cam pin. If not, then this is also a problem. See attached pic.

If it still doesn't function AFTER ALL THIS IS CORRECTED, it's time to get an adjustable gas block. If you do the gas block first, it will tend to cover up all these underlying problems and you will likely have to continually adjust the gas block to keep the gun functioning between different ammo types. Your goal is total reliability at this point.

Also see this thread:

PSA PA10 (308) Experiment

Sooo I wanted another 308 rifle, and was pondering back and forth between going Aero, PSA, or buying something used off here. My financial priorities do not align with mid to high tier 308AR/AR10's so under $1500 but closer to $1000. This would not be precision focused and will wear a 1-4/1-6...

www.snipershide.com

There are many threads here that will help, the search function is your friend.

 

[bfoosh006]

What Gen PS PA-10 ?
What buffer tube length , and what buffer weight ?

I thought all the Gen 3 ones came with an Adj. GB

Basically your firearm is over gassed... so as mentioned an Adj. GB is an easy fix.
You can regulate the volume of gas being used to cycle your firearm easily with one... that will address your issues.

And most likely you won't have to change any other parts.

On a side note... are you using a suppressor ?

 

[Expert684]

Looks like hot ammo. Try different stuff like some basic FMJ loads.

This^^^^^^^^^^^^^^^^^^
Had Hornady blow primers on a LR308.
Stuff was way too hot. You are over-gassed due to the ammo.

 

[FredHammer]

Man, I thought I could fuck shit up, but you take the crown on that!

The dents on the cases being chambered. I can only imagine they are getting rocked on the center lug cut out at the 6 o'clock as they feed into the chamber. Sharpie color the entire case and see where all it is hitting on its trip from the mag.

Obvious it is over-gassed. You should install AGB. I would use a bleed off AGB like Superlative Arms. I've tried to tame down several over gassed, too large gas port diameter, with restrictive gas blocks, but to no avail. The bleed off SA have always worked better. If the bleed off style doesn't work then you are SOL. The gas port must be so large nothing can help.

I like to use a 5.3oz buffer, AGB, and tune it so it spits the casings straight out 90 degrees to the side. 3'Oclock. About 4-5ft.

This sucks. good luck.

 

[x248716x]

suppressed, or unsuppressed?

 

[504ChapoRambo]

I need help!! First got the gun it was firing with no problem, the second time I hit the range every time I fired felt hot air hitting my hand, so checked it out and the gas block came loose like playing a trombone. Fix everything back everything went wrong from there! I am getting double feeds!! I shot the gun a coupoe
Weeks ago with no Mag and shell failed to extract like not enough pressure pushing back. I have ordered a superlative arms adjustable gas block, changed all the parts in BCG, Changed the buffer spring to armaspec stealth recoil spring idk which Gen, and a spikes tactical gas tube! Need some help or some tips...

Wasn’t a good photo but as you fire shell fails to eject and loading live round aswell.

 

[Makinchips208]

I need help!! First got the gun it was firing with no problem, the second time I hit the range every time I fired felt hot air hitting my hand, so checked it out and the gas block came loose like playing a trombone. Fix everything back everything went wrong from there! I am getting double feeds!! I shot the gun a coupoe
Weeks ago with no Mag and shell failed to extract like not enough pressure pushing back. I have ordered a superlative arms adjustable gas block, changed all the parts in BCG, Changed the buffer spring to armaspec stealth recoil spring idk which Gen, and a spikes tactical gas tube! Need some help or some tips...

Wasn’t a good photo but as you fire shell fails to eject and loading live round aswell.

Can you add more info?
Caliber?
Barrel length?
Gas system length?
Any other specific info of this gun.

Ammo used?
Was other ammo tried?
Did one specific type of ammo work?

Who built the gun?

You said it worked fine when you first fired it. If so, how many rounds did you fire?

 

[504ChapoRambo]

I need help!! First got the gun it was firing with no problem, the second time I hit the range every time I fired felt hot air hitting my hand, so checked it out and the gas block came loose like playing a trombone. Fix everything back everything went wrong from there! I am getting double feeds!! I shot the gun a coupoe
Weeks ago with no Mag and shell failed to extract like not enough pressure pushing back. I have ordered a superlative arms adjustable gas block, changed all the parts in BCG, Changed the buffer spring to armaspec stealth recoil spring idk which Gen, and a spikes tactical gas tube! Need some help or some tips...

Wasn’t a good photo but as you fire shell fails to eject and loading live round aswell.

Can you add more info?
Caliber?
Barrel length?
Gas system length?
Any other specific info of this gun.

Ammo used?
Was other ammo tried?
Did one specific type work?

Who built the gun?

You said it worked fine when you first fired it. If so, how many rounds did you fire?

@Makinchips208
AR 10 DPMS .308
7.75 - Added inch barrel adapter to clear handguard
Gas tube Pistol length

Brass around 147 - 150 grain
Wolf steel Ammo 147 grain I think
I used Hornady Black unsure of grain- Ran 5 rounds perfect then jams started again

Did one specific type of work? Don't understand what you are asking!

Company: MORIARTI ARMAMENTS
Didn't do research before i ordered, but it's damn shall not a good company. I thought it was a sweet deal at the time horrible customer service, gun was sent in bubble wrap to gun store smh!

​

 

[Makinchips208]

Did one specific type of work? Don't understand what you are asking!

Just meant, did one or any specific type of ammo work?

 

[504ChapoRambo]

Can you add more info?
Caliber?
Barrel length?
Gas system length?
Any other specific info of this gun.

Ammo used?
Was other ammo tried?
Did one specific type work?

Who built the gun?

You said it worked fine when you first fired it. If so, how many rounds did you fire?

@Makinchips208
AR 10 DPMS .308
7.75 - Added inch barrel adapter to clear handguard
Gas tube Pistol length

Brass around 147 - 150 grain
Wolf steel Ammo 147 grain I think
I used Hornady Black unsure of grain- Ran 5 rounds perfect then jams started again

Did one specific type of work? Don't understand what you are asking!

Company: MORIARTI ARMAMENTS
Didn't do research before i ordered, but it's damn shall not a good company. I thought it was a sweet deal at the time horrible customer service, gun was sent in bubble wrap to gun store smh!

​

So, i had luck when I had around 5-7 rounds in the mag would fire them all without a jam sometimes pretty sure was brass. Full mag nothing but jams. Mag holds 25 rounds, but still would Jam with a low mag as well. So I'm going to order a new Mag shopping for one as I text this, I
Magpaul with the window that show rounds came with the gun! But I don't think that's the problem, so I bought an adjustable gas block I'm thinking that's the issue and changed Gas tube

 

[504ChapoRambo]

Just meant, did one or any specific type of ammo work?

Yes brass but only when the mag would be low sometimes. Plus when i
First shot it at the range i just brass around 147 grain 10 rounds cycled flawlessly. But then everything on the gun was loose fixed the gas block back every type of way, nothing worked. Not getting enough pressure to move gas move BCG back for round to be ejected

 

[504ChapoRambo]

Can you add more info?
Caliber?
Barrel length?
Gas system length?
Any other specific info of this gun.

Ammo used?
Was other ammo tried?
Did one specific type work?

Who built the gun?

You said it worked fine when you first fired it. If so, how many rounds did you fire?

@Makinchips208
AR 10 DPMS .308
7.75 - Added inch barrel adapter to clear handguard
Gas tube Pistol length

Brass around 147 - 150 grain
Wolf steel Ammo 147 grain I think
I used Hornady Black unsure of grain- Ran 5 rounds perfect then jams started again

Did one specific type of work? Don't understand what you are asking!

Company: MORIARTI ARMAMENTS
Didn't do research before i ordered, but it's damn shall not a good company. I thought it was a sweet deal at the time horrible customer service, gun was sent in bubble wrap to gun store smh!

​

So, i had luck when I had around 5-7 rounds in the mag would fire them all without a jam sometimes pretty sure was brass. Full mag nothing but jams. Mag holds 25 maybe 30 rounds, but still would Jam with a low mag as well. So I'm going to order a new Mag shopping for one as I text this, I
Magpaul with the window that show rounds came with the gun!

Can you add more info?
Caliber?
Barrel length?
Gas system length?
Any other specific info of this gun.

Ammo used?
Was other ammo tried?
Did one specific type of ammo work?

Who built the gun?

You said it worked fine when you first fired it. If so, how many rounds did you fire?

Oh yeah so when it started double feeding I changed to Buffer spring to

ARMASPEC STEALTH RECOIL SPRING BUFFER ASSEMBLY​

Same issues

 

[Evintos]

Yes brass but only when the mag would be low sometimes. Plus when i
First shot it at the range i just brass around 147 grain 10 rounds cycled flawlessly. But then everything on the gun was loose fixed the gas block back every type of way, nothing worked. Not getting enough pressure to move gas move BCG back for round to be ejected

Did you make sure to align the gas block with the gas port? Remove bcg, blow compressed air through gas tube, the amount of air coming out the barrel should at the very least move tissue.

Also, if you bought that Armaspec SRS that you attached a pic of, you bought the wrong one. You need the AR10 version. SKU for that is ARM253-AR10 and it looks like the pic below. Look at the left side black spacer, it's a thin one. If you got a thicker black spacer there, you definitely bought the AR15 version.

 

[Makinchips208]

Yes brass but only when the mag would be low sometimes. Plus when i
First shot it at the range i just brass around 147 grain 10 rounds cycled flawlessly. But then everything on the gun was loose fixed the gas block back every type of way, nothing worked. Not getting enough pressure to move gas move BCG back for round to be ejected

Ok. Sounds like not enough gas is making it to the bcg.
Is the gas block aligned to the gas port in the barrel?
Is the bcg lubed properly?

I’m sure there are other questions that can be asked, and hopefully some others will chime in tomorrow, if not tonight.

A semi auto 308 this short is a little more work to get it to cycle reliably, but it can be done.

Thanks for responding! Just don’t be like the op of this thread and ask questions then fail to give feedback. Lol.

And you said double feed? Do you mean that the fired case is not ejected, and the bolt jams up on top of the next round in the mag?

And if you had a few rounds of success, and the new buffer didn’t fix it, then I would reinstall the original, so as to not introduce more complexity to the problem.

 

[504ChapoRambo]

Added a photo and yes double feed Empty on top of live round and BCG trying to load both. I haven’t shot 50 rounds through it so didn’t think to check the Gas tube. All my guns are well lube soon as I make it home from range and ready to run my all My AR are a lil wet. But I have been reading up on it for a while and read a lot of ppl have problems with short AR 10’s.

Yes once I changed to stealth spring it was firing well with low Mag, reinstalled the old spring, and never got more than one round to fire.

Aligning gas block I watch YouTube videos making sure I was doing it right, it's a dimple on the barrel I aligned correctly and screwed it back in I was gone locktite once it fired reliably, but never fixed the issue so didn't think to check the tube thought maybe it was the gas block! So I ordered a new tube and block in route as we speak!

 

[504ChapoRambo]

Ok. Sounds like not enough gas is making it to the bcg.
Is the gas block aligned to the gas port in the barrel?
Is the bcg lubed properly?

I’m sure there are other questions that can be asked, and hopefully some others will chime in tomorrow, if not tonight.

A semi auto 308 this short is a little more work to get it to cycle reliably, but it can be done.

Thanks for responding! Just don’t be like the op of this thread and ask questions then fail to give feedback. Lol.

And you said double feed? Do you mean that the fired case is not ejected, and the bolt jams up on top of the next round in the mag?

And if you had a few rounds of success, and the new buffer didn’t fix it, then I would reinstall the original, so as to not introduce more complexity to the problem.

I would of sent videos but you can't here, and I will always respond man I love the gun culture, do all my Gunsmithing work, and I love finding out how to solve problems and fix them. Plus once I read how bad the company was I figured I'll just change all The factory parts out and have make it a better gun! So I believe everything will come together just takes money and time to get it done been sitting on this issue for about a year and a half just haven't had the funds to spend, I put maybe like 500 to 700 of parts on it already to was kind of Frustrated, but the gun is actually amazing and I'll order another barrel about 10.5 inch or 12 just to have

 

[Makinchips208]

Added a photo and yes double feed Empty on top of live round and BCG trying to load both. I haven’t shot 50 rounds through it so didn’t think to check the Gas tube. All my guns are well lube soon as I make it home from range and ready to run my all My AR are a lil wet. But I have been reading up on it for a while and read a lot of ppl have problems with short AR 10’s.

Yes once I changed to stealth spring it was firing well with low Mag, reinstalled the old spring, and never got more than one round to fire.

Aligning gas block I watch YouTube videos making sure I was doing it right, it's a dimple on the barrel I aligned correctly and screwed it back in I was gone locktite once it fired reliably, but never fixed the issue so didn't think to check the tube thought maybe it was the gas block! So I ordered a new tube and block in route as we speak!

Ok cool. Maybe the new buffer helps then.

Also, maybe there is possibility of the extractor spring being weak? It should have hung onto the fires case until the case started to swing out the ejection port.

It does appear the bolt is Behind the case of the new round, as it should be. Am I I correct on that observation?

 

[504ChapoRambo]

Ok. Sounds like not enough gas is making it to the bcg.
Is the gas block aligned to the gas port in the barrel?
Is the bcg lubed properly?

I’m sure there are other questions that can be asked, and hopefully some others will chime in tomorrow, if not tonight.

A semi auto 308 this short is a little more work to get it to cycle reliably, but it can be done.

Thanks for responding! Just don’t be like the op of this thread and ask questions then fail to give feedback. Lol.

And you said double feed? Do you mean that the fired case is not ejected, and the bolt jams up on top of the next round in the mag?

And if you had a few rounds of success, and the new buffer didn’t fix it, then I would reinstall the original, so as to not introduce more complexity to the problem.

@Makinchips208 A few of my projects try to make Firearms mine and upgrade them I see fit bought Ruger 5.7 was rusted removed rust and First paint jobs - Dark Candy Green Apple, Beretta Apx was bored did it to, SW 10MM sent to NCEngravers to design and paint it out Apex trigger on it, PSA AK, And Draco change all internal parts added ALG triggers, FN 5.7 Added a Flat trigger just some stuff I did nothing special

 

[504ChapoRambo]

Ok cool. Maybe the new buffer helps then.

Also, maybe there is possibility of the extractor spring being weak? It should have hung onto the fires case until the case started to swing out the ejection port.

It does appear the bolt is Behind the case of the new round, as it should be. Am I I correct on that observation?

No that's a double feed I found online but it looks exactly like that, I change all parts on BCG now haven't shot it yet, waiting on new Gas block and only hold up! You think the Adjustable gas block would help?

 

[504ChapoRambo]

If that doesn't fix the issue I will buy a new buffer kit and if all fails then I'll just get a longer barrel and call it quits lol

 

[msgriff]

Added a photo and yes double feed Empty on top of live round and BCG trying to load both. I haven’t shot 50 rounds through it so didn’t think to check the Gas tube. All my guns are well lube soon as I make it home from range and ready to run my all My AR are a lil wet. But I have been reading up on it for a while and read a lot of ppl have problems with short AR 10’s.

Yes once I changed to stealth spring it was firing well with low Mag, reinstalled the old spring, and never got more than one round to fire.

Aligning gas block I watch YouTube videos making sure I was doing it right, it's a dimple on the barrel I aligned correctly and screwed it back in I was gone locktite once it fired reliably, but never fixed the issue so didn't think to check the tube thought maybe it was the gas block! So I ordered a new tube and block in route as we speak!

Due to your barrel/gas system length, I would contact Armaspec just to verify that they don't see any problems with their SRS and your set-up. Can you measure the length and weight of the original buffer? I personally would be going with a conventional action system of extraordinary weight.

Since you have a Superlative on order, I would hold off on doing much until it's installed and tuned. Your window of proper function will be fairly small, so pick a specific ammo and stick with it through your tuning process. If you get a chance, measure the diameter of the gas port. If it happens to be under-gassed, which I doubt, an AGB cannot increase, only decrease gas flow.

 

[504ChapoRambo]

Ok cool. Maybe the new buffer helps then.

Also, maybe there is possibility of the extractor spring being weak? It should have hung onto the fires case until the case started to swing out the ejection port.

It does appear the bolt is Behind the case of the new round, as it should be. Am I I correct on that observation?

What would you suggest when getting a new buffer tube spring on a pistol length system? I like the silent systems that doesn’t like a spring!

 

[504ChapoRambo]

Due to your barrel/gas system length, I would contact Armaspec just to verify that they don't see any problems with their SRS and your set-up. Can you measure the length and weight of the original buffer? I personally would be going with a conventional action system of extraordinary weight.

Since you have a Superlative on order, I would hold off on doing much until it's installed and tuned. Your window of proper function will be fairly small, so pick a specific ammo and stick with it through your tuning process. If you get a chance, measure the diameter of the gas port. If it happens to be under-gassed, which I doubt, an AGB cannot increase, only decrease gas flow.

@msgriff When you say measure, you mean on the barrel or the gas tube? So you think a regular gas block would feed more gas as in a non adjustable?

I have my old AR15 and AR 10 spring mixed up so I don’t know which is which now but I can measure both and let you know!

I have been tryin to find the Armspec that I ordered but can’t seem to find it I ordered off of Wing tactical but it’s a bunch of different ones now

 

[msgriff]

@msgriff When you say measure, you mean on the barrel or the gas tube? So you think a regular gas block would feed more gas as in a non adjustable?

I have my old AR15 and AR 10 spring mixed up so I don’t know which is which now but I can measure both and let you know!

I have been tryin to find the Armspec that I ordered but can’t seem to find it I ordered off of Wing tactical but it’s a bunch of different ones now

The gas port is on the barrel. Technically, you would measure it with pin gauges, but most people would not have those, so you use the shanks of a numbered drill set and measure the tightest fitting shank with a micrometer or caliper.

I was asking about the original buffer, not the spring. It might be 3.25" long, but most likely 2.5". Measuring the internal depth of the receiver extension (buffer tube) would also be helpful for reference and future suggestions.