PSA PA10 (308) Experiment

[Gustav7]

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 LPVO for general fun steel shooting or the occasional hog/coyotes. I know a decent bit about the variations and differences between the 308AR patterns and the nuance to getting them to run right. In that learning journey I've also learned quite a bit about how PSA has screwed the pooch on a reliable out of the box rifle, but that correcting those issues isn't always that hard, provided you end up with a rifle that doesn't shoot.

I was leaning more towards the Aero, but PSA had a shot show sale, and I ended up with the 18" upper build kit that has everything besides the lower for $600 shipped. Bought a blem lower for $100 shipped (plus $25 for my ffl transfer fee). So I'm sitting at $725 shipped for a complete rifle. This is just an experiment to dick around and get a 308AR to run well.

I'm not really trusting of the way PSA set up the rifles, so I did buy some upgrades to put on it. However, I did want to actually give the rifle a go and see if it: 1.) Reliably functions 2.) How accurate, or lack thereof, it is 3.) Felt recoil/general shoot-ability.
Before I start shooting, I was going to take a few measurements to see how "in spec" it is and what specs they're using for my specific rifle. I'll check:
-Inside depth of buffer tube
-Length and weight of my buffer
-Gas port diameter
-Gas tube length and position in relation to cam pin cutout in the upper.
-How far back the BCG rides in comparison to the lower buffer tube ear area.
-General fit/finish
Once I get it put together, I'm gonna lube it up and run a few different factory rounds through it and see how she goes. I'll try to get a "feel" for recoil and how it shoots, obviously any function issues, and some basic accuracy tests.

After that, I'll put on the upgrades and reassess. So far that is:
-Superlative arms AGB
-308 carbine buffer tube, 5.4oz carbine buffer, and 308 buffer spring; all from Armalite.
-If the gas tube is too short, I'll also get the proper Armalite carbine(midlength) gas tube which is just over a 1/4" longer.
-Another addition, since midlength gas on an 18" barrel sucks, is cut and rethread to 16". Luckily my buddy works at a machine shop so he can do it for some beer. Possibly chuck it on a lathe and take some weight off the barrel since these PSA ones are pretty heavy too, but we'll see.

Since PSA runs Toolcraft nitride BCG/Bolt, I wasn't planning on upgrading that provided I don't have issues.

Can anyone think of anything else to check/measure? Any additions you'd make besides what I have? Maybe @mtrmn can assist.

**I'LL MAKE EDITS ALONG THE WAY**

 

[BCP]

My guess is that as long as it's assembled correctly it'll work fine but be overgassed. So then you have to play with adjustable gas blocks or heavy buffers.

 

[nagantguy]

When PSA was the only off the shelf reasonably priced lr308 for the “poors” several buddies bought them- some had some gas issues - other little teething pains but I don’t recall one that didn’t shoot decent - all were made to function with the gas block- or spring buffer game . If you got this up and running for your stated price OP - hats off to ya . I will be following this thread .

 

[WarDamnRockets]

My dad bought a basic PA10 around the time I built up 308 on an Aero M5 set. He had issues with it initially, but eventually got it all worked out. It was a few years ago, so unfortunately I don’t remember exactly what the issues were, but I’d say it’s definitely possible to get one running.

 

[Gustav7]

My guess is that as long as it's assembled correctly it'll work fine but be overgassed. So then you have to play with adjustable gas blocks or heavy buffers.

Well I don't plan on leaving the stock buffer system on regardless. I'm gonna try it out in the beginning but I'll be putting on the correct Armalite buffer system so I can use standard buffers if I need to adjust weight at all.

When PSA was the only off the shelf reasonably priced lr308 for the “poors” several buddies bought them- some had some gas issues - other little teething pains but I don’t recall one that didn’t shoot decent - all were made to function with the gas block- or spring buffer game . If you got this up and running for your stated price OP - hats off to ya . I will be following this thread .

That's what I've come to learn is that some work, a lot aren't great, but can be made to run provided you understand the buffer/gas system.

Primary Arms had a 12% off sitewide sale the other day, so I got the Superlative Arms AGB, and the 3 Armalite buffer components for $155 total. That brings the improved rifle, that will most likely run well, to $880 total.

The other main concern was gas port size. To my knowledge, most guys I've seen measure them in the Gen 3's said it was around 0.90" which should be about right I think. We shall see though. I'll measure that first.

 

[Jefe's Dope]

I built one and the initial "gen 1" upper would not feed/eject reliably. PSA refunded my purchase (from a 3rd party on GunBroker) and I purchased a 2nd gen upper direct from PSA. It has functioned perfectly with the exception of being overgassed w/ a suppressor. I've added a adjustable gas block and all it GTG. Was banging steel out to 600 yards using factory Federal 175 Sierra King in heavy winds out at Pawnee last year.

 

[mtrmn]

Looking at your to-do list it looks like you have everything covered. IMO you need to check headspace too. I didn't at first and that set me back considerably on troubleshooting. The fact that my original bolt allowed too much headspace coupled with all the other problems on your list had me chasing my tail for quite a while.
That too short gas tube is a sneaky one that most never think to check. Learned about that one over on 308AR forum.
Pretty much everything on your list was required to fix mine. It runs now pretty good.
I did go ahead and get the Heavybuffers.com XH buffer and spring to calm it down some more, especially suppressed. It weighed 8.5 oz but I removed one of the 3 tungsten weights and replaced it with a steel one so that it weighs 7.6oz now.

 

[Gustav7]

Looking at your to-do list it looks like you have everything covered. IMO you need to check headspace too. I didn't at first and that set me back considerably on troubleshooting. The fact that my original bolt allowed too much headspace coupled with all the other problems on your list had me chasing my tail for quite a while.
That too short gas tube is a sneaky one that most never think to check. Learned about that one over on 308AR forum.
Pretty much everything on your list was required to fix mine. It runs now pretty good.
I did go ahead and get the Heavybuffers.com XH buffer and spring to calm it down some more, especially suppressed. It weighed 8.5 oz but I removed one of the 3 tungsten weights and replaced it with a steel one so that it weighs 7.6oz now.

The gas tube was a big learning point I got from that forum as well. Never would have thought such a small change would make such a big difference.

Good idea on headspace, with headspace gauges, is there a recommended brand? And I’m assuming SAAMI 308 and not 7.62 NATO?

 

[celltech]

Headspace it with a piece of brass and layers of tape....goes with the budget theme

 

[tacticalrifleman]

I bought a 20” .308 PSA upper, then one of their complete lowers 3-4 years ago and it has functioned flawlessly ever time it’s gone to the range since. I bought it right after the walmrt shooting happened in el paso and it was 535.00 delivered.

I did put a single stage flat bow trigger in it with anti walk pins and a leupold 3-10x40 scope with mildot and routinely shoot it to 1k yards with fed gold match 175’s. At Thunder Valley which does have large notebook page sized targets I did get hits at 1100 with fair consistancy….although 1200 seemed to be outside the cone of accuracy slightly.

At Rayners it is capable of the one minute sized plate hits to 1000 easily enough, the half minute plates are a struggle however. All in all I wouldn’t think it would be reasonable to expect half minute accuracy out of an AR10 setup…especially one that was 535.00 at purchase.

I did also add a cheap muzzle break that actually seems to work pretty good as recoil doesn’t seem as sharp as previous AR10’s I’ve had and shot.

 

[AccuSol-ERN]

I have a PSA10 in 6.5creed. It started at 20" rifle length gas system and I cut it down to 18" and put on a APA gen2 LB.

It runs great and shoots any decent match ammo about 1moa. It should shoot better after it wears in and I load for it. Overall it is pretty impressive for the money. I will change a few things on it that feel cheap......charging handle, grip, etc.

Ern

 

[mtrmn]

The gas tube was a big learning point I got from that forum as well. Never would have thought such a small change would make such a big difference.

Good idea on headspace, with headspace gauges, is there a recommended brand? And I’m assuming SAAMI 308 and not 7.62 NATO?

I bought Forster .308 gages when I suspected headspace problems. Go, No-go, and field. My original bolt closed and locked easily on the no-go and almost closed on the field. On 2 barrels. So I replaced it with a Lantac bolt in my original carrier. No more problems with that. I didn't bother messing with PSA about warranty, I just wanted to get it running.
On the gages, I don't know if there's a difference in 308 vs 762 gages.

 

[Steve_In_29]

I own 2 PA10s (Gen 3) in .308 with 20" stainless barrels.

First had a bad extractor and PSA swapped the entire bolt out. Functioned fine after that. Second rifle has been perfect from day one.

While they functioned fine I did replace the buffer and spring with KAW parts to tame the recoil a bit more. I also replaced the stock EPT triggers with their 2-stage version from Schmid Tool.

 

[msgriff]

The gas tube was a big learning point I got from that forum as well. Never would have thought such a small change would make such a big difference.

Good idea on headspace, with headspace gauges, is there a recommended brand? And I’m assuming SAAMI 308 and not 7.62 NATO?

There isn't a SAAMI "NO-GO" spec. That chamber dimension is set by the barrel manufacturer and varies. For .308Win, as long as the chamber is in between SAAMI min/GO (1.630") and max/FIELD (1.640"), the chamber is technically within spec. There is a SAAMI cartridge spec for commercial .308Win ammo, which is 1.634"(-0.007"). So a chamber that is reamed less that 1.634" may not accept some commercial ammo.
I have seen commercial .308Win "NO-GO" gauges that are 1.633", 1.634" and 1.635", depending on the brand. One of the best deals for gauges is the Manson Reamers "Down and Dirty" set of three (GO, NO-GO, and FIELD) for $85, but is typically not the fastest option if you're in a hurry. Top of the line headspace gauges are a set of 11, in 0.001" increments.
ETA: All dimensions are base to datum (0.400").

 

[Gustav7]

I bought Forster .308 gages when I suspected headspace problems. Go, No-go, and field. My original bolt closed and locked easily on the no-go and almost closed on the field. On 2 barrels. So I replaced it with a Lantac bolt in my original carrier. No more problems with that. I didn't bother messing with PSA about warranty, I just wanted to get it running.
On the gages, I don't know if there's a difference in 308 vs 762 gages.

This was my thought. It sounds like maybe the QC of the toolcraft BCG/Bolts for PSA is probably lacking a bit, but I'm sure if you get an in spec one they're solid. Worst case I just pony up for a RCA complete bcg.

There isn't a SAAMI "NO-GO" spec. That chamber dimension is set by the barrel manufacturer and varies. For .308Win, as long as the chamber is in between SAAMI min/GO (1.630") and max/FIELD (1.640"), the chamber is technically within spec. There is a SAAMI cartridge spec for commercial .308Win ammo, which is 1.634"(-0.007"). So a chamber that is reamed less that 1.634" may not accept some commercial ammo.
I have seen commercial .308Win "NO-GO" gauges that are 1.633", 1.634" and 1.635", depending on the brand. One of the best deals for gauges is the Manson Reamers "Down and Dirty" set of three (GO, NO-GO, and FIELD) for $85, but is typically not the fastest option if you're in a hurry. Top of the line headspace gauges are a set of 11, in 0.001" increments.
ETA: All dimensions are base to datum (0.400").

Very useful info, thank you for that. How long are we talking with Manson Reamers? I'm in no rush but "not the fastest option" could mean a lot of different things lol. Unless someone wants to ship me theirs to use, provided I cover cost?

 

[mtrmn]

I own 2 PA10s (Gen 3) in .308 with 20" stainless barrels.

First had a bad extractor and PSA swapped the entire bolt out. Functioned fine after that. Second rifle has been perfect from day one.

While they functioned fine I did replace the buffer and spring with KAW parts to tame the recoil a bit more. I also replaced the stock EPT triggers with their 2-stage version from Schmid Tool.

I've loved a 2 stage trigger since I was a kid. I haven't mentioned it but I do have a PSA 2 stage nickel boron trigger in mine.
Also, on the subject of buffers and tubes, I started out fixing my existing buffer system with a Sprinco orange recoil spring coupled with a Kaw Valley 5.6 oz buffer. (2.5" long)This worked well enough and probably would still be in place had I not decided that I wanted to go even heavier. I ordered a 8.5oz XH buffer from Heavybuffers.com along with the recommended Armalite rifle spring. That buffer is 3.25" long and requires the longer 7-5/8" deep tube so I got Armalite kit that I should have gotten much earlier.
I went off on a quest to get the gun to function with or without my suppressor WITHOUT having to change gas settings with an adjustable gas block. My quest was a failure in that regard. Never found that magic balance point where I could do away with adjustable gasblock, but after extensive experimentation I settled on a buffer wt of 7.6 oz. The gun is exceedingly smooth and soft shooting now and so far totally reliable.

 

[Gustav7]

I've loved a 2 stage trigger since I was a kid. I haven't mentioned it but I do have a PSA 2 stage nickel boron trigger in mine.
Also, on the subject of buffers and tubes, I started out fixing my existing buffer system with a Sprinco orange recoil spring coupled with a Kaw Valley 5.6 oz buffer. (2.5" long)This worked well enough and probably would still be in place had I not decided that I wanted to go even heavier. I ordered a 8.5oz XH buffer from Heavybuffers.com along with the recommended Armalite rifle spring. That buffer is 3.25" long and requires the longer 7-5/8" deep tube so I got Armalite kit that I should have gotten much earlier.
I went off on a quest to get the gun to function with or without my suppressor WITHOUT having to change gas settings with an adjustable gas block. My quest was a failure in that regard. Never found that magic balance point where I could do away with adjustable gasblock, but after extensive experimentation I settled on a buffer wt of 7.6 oz. The gun is exceedingly smooth and soft shooting now and so far totally reliable.

From what I've read, and it makes sense, I just don't feel like the standard RE and 2.5" buffer will ever be quite as versatile and "proper" as the correct armalite RE and standard buffer. Maybe I'm just being too purist with that thought.

I'm sure the one gas position for suppressed/unsuppressed is possible, but I would imagine it may take a different gas position to make that work? Like a rifle gas on 16" or rifle +1/+2 on 18" and 20"? In the end it may just be easier to buy a Flow through design suppressor lol.

How was the Nickel Boron PSA 2 stage?

 

[Gustav7]

Headspace it with a piece of brass and layers of tape....goes with the budget theme

LOL, this is pretty much a "how little can I spend to get a legit 308 AR that runs well" experiment.

 

[msgriff]

snip...

Very useful info, thank you for that. How long are we talking with Manson Reamers? I'm in no rush but "not the fastest option" could mean a lot of different things lol. Unless someone wants to ship me theirs to use, provided I cover cost?

I don't know how long these days. Manson has been around for a very long time, but only recently has had a website that you can actually order from. It used to be a call on the phone to order, or send in a check or money order if you didn't have an account.
As far as intermediate length action/recoil systems, the ArmaLite AR-10 carbine kit is probably the cheapest all-in one. There's also a similar kit from SOLGW for slightly more. You can piece-meal the parts cheaper, but multiple shipping charges might negate any savings.

 

[Killswitch Engage]

not a .308 but i have a gen 2 psa in 6.5cm and as much as i might like to look down my nose at it i simply cannot. it not only shoots everything ive fed it flaswlessly it shoots it incredibly well. as in this gun with hornady american gunner 140bthp has been a no shit .5-.6 moa rifle. it shoots pretty much anything 1moa or less. i did put a trigger tech diamond trigger in it but everything else is bone stock. the adjustable gas block has let me run it suppressed without hiccup or being overgassed at all. you can truly shut it off enough the bolt wont come out of battery if you want so its definitely tunable.

 

[Gustav7]

... the adjustable gas block has let me run it suppressed without hiccup or being overgassed at all. you can truly shut it off enough the bolt wont come out of battery if you want so its definitely tunable.

Does yours have the 3 or 5 position one? They don't give a lot of info and some seem to have 3 and some seem to have 5. I have the Superlative AGB on the way for it, but I did want to screw around with the factory one too.

As far as intermediate length action/recoil systems, the ArmaLite AR-10 carbine kit is probably the cheapest all-in one. There's also a similar kit from SOLGW for slightly more. You can piece-meal the parts cheaper, but multiple shipping charges might negate any savings.

I bought the spring, buffer, and tube during one of Primary Arms sales, so I think I paid just at what Armalite charges for the kit, shipped. Like $75 or something.

 

[mtrmn]

From what I've read, and it makes sense, I just don't feel like the standard RE and 2.5" buffer will ever be quite as versatile and "proper" as the correct armalite RE and standard buffer. Maybe I'm just being too purist with that thought.

I'm sure the one gas position for suppressed/unsuppressed is possible, but I would imagine it may take a different gas position to make that work? Like a rifle gas on 16" or rifle +1/+2 on 18" and 20"? In the end it may just be easier to buy a Flow through design suppressor lol.

How was the Nickel Boron PSA 2 stage?

I went through the scenic route to get to where I am today. The shorter buffer system on a 16" bbl 308 can be made to work reliably but the longer system is much easier.

My suppressor is a YHM Phantom titanium QD, bought back in or before 2010. I'm sure there are more modern designs that don't overload your gas system as much as mine does. I have one other 308AR that is a 20" rifle. It does not have an adjustable gasblock, and it DOES operate reliably with/without my suppressor. It DOES have a Heavybuffers.com buffer system which enabled it to accomplish this without an adjustable gasblock. It ejects about 3-4 o'clock without suppressor and about 130-2 o'clock with the suppressor reliably.
This gun is an old Bushmaster which is the same design as the Rock River and uses FN FAL mags. The buffer system is proprietary and that buffer won't work in any other design.

 

[bfoosh006]

FWIW... I have several PSA Large Frames and Uppers with various gas system lengths, barrel lengths, and calibers, and ultimately the buffer system ( DPMS carbine pattern and Armalite carbine pattern ) have all worked as intended.

My following comments aren't intended as strictly directed to the OP, but for others reading as well.

So please don't take this personal OP , just some of my observations.

I do think the Armalite pattern is a more versatile pattern only because it uses a more commonly available 3.25" buffer length.
FWIW, anyone can buy a DPMS pattern 2.5" buffer in a 5.3oz weight... but most current 2.5" buffers ( again DPMS carbine pattern ) from various manufacturers ( Aero, and PSA being 2 of the more common places ) come lighter then a typical Armalite 3.25" buffer.

DPMS also "wanted" to use as many AR15 parts as possible, IE gas tubes, buffer tubes. ( less expensive route ? really not sure why )
Armalite "wanted" to build a scaled up Large Frame AR, and took the time to develop scaled up parts as well, buffer weight included.

I will say, the Armalite gas tube fits far better around the larger barrel nut used in a Large Frame AR and avoids contact with the barrel nut, some thing most typical Low profile GB and a AR15 gas tube don't do on a Large Frame AR.
Accuracy wise that matters. For those that don't know....You really want a free / easy interaction between the gas tube and gas key.

That said the shorter DPMS pattern buffer setup has been used successfully in God knows how many Large Frames over the years. ( same can be said about the Armalite pattern )

The shorter Gas tube length hasn't ever seemed to matter in any of mine either. ( DPMS pattern ) All my uppers function 100%
The DPMS pattern gas tube length , while shorter then the Armalite gas tube length, is only part of the gas setup. ( Duh , right ? )

Some differences....
DPMS BCG's have only 2 exhaust holes in the carrier, restricting flow more then the Armalite 3 gas hole carriers.
While that may sound trivial , it is still a design difference between the 2 patterns.
I think the exhaust port locations are also slightly positioned in different spots on the carrier as well. ( front to back wise )
And that positioning makes for a different volume in the carriers and bolt , between the 2.
So while a Armalite longer gas tube makes for a "longer" pressure push, it is also bleeding out gas faster than the shorter DPMS gas tube and its 2 exhaust ports.

All this is just semantics, between the 2 patterns, since both systems obviously work.

Kind of a Ford v. Chevy thing.

If one or the other didn't work, the non working pattern would have died off.
There are other subtle differences between the 2 BCG's as well. I have that info at home and will post later.


The 1 thing that I have noticed , that made the most difference in function, was the gas port size.

"Almost" Every DPMS pattern barrel, length, gas system length and brand, was over gassed. The gas ports are just to big.
My Krieger is the only barrel I have that has a "correct" ( ? ) gas port size. Maybe better said, a smaller gas port size would help.
Every other barrel length / gas length / brand has benefited from an Adj. GB, in numerous ways, function being the #1.

I realize a large gas port allows for 100% reliable function under adverse conditions ( etc. ) ... but it also led to the cyclic speed in my PSA's being so high that it would cause odd issues. ( Again various brand barrels, with large gas ports PSA included. )
"Short stroking" is one of those3 issues ... but IMHO that is more a result of a gas port being to big , causing the cyclic speed to out run some of the other parts , and bouncing the buffer off the bottom of the buffer tube.

The Gen II PSA's were a great example of how little it took to throw "off" the cycling of a Large Frame AR.
The Gen II's were known for the BCG smacking the the threads on the lower at the buffer tube, and battering those threads, that alone would jack up function almost everytime.
I say almost because none of mine ever did it , but there are numerous reports on the various forums.

Current Gen III lowers have cutouts at the Gen II impact points, and that fixed that issue.


As for other things I would look at....

Extractor, some Toolcraft 308 BCG's can come with a less then precisely cut extractor "claw" .

Make sure the barrel is indexed properly at the barrel extension locating pin into the upper, the feed ramps "should" show obvious out of alignment issues. A poorly indexed barrel extension will result in bolt lug battering. ( Another member had one that was way out of clock, and it beat the hell out of the bolt locking lugs, heck the alignment locating pin freely fell out of the barrel extension )

Make sure simple things are tight... Flash Hider, barrel nut, stuff like that.

Maybe.... consider running it first as it came from the factory ? ... a rapidish fired magazine worth ? ( Obviously check the bore first ) I am curious if it is so lacking in lube to cause malfunctions straight from the box. ( IE , how many people don't clean and relube before firing the firearm and then have function issues )


Would you mind linking to the items you bought from PSA ?


All this said, I am looking forward to your accuracy results, measurements, etc.

 

[Steve_In_29]

I've loved a 2 stage trigger since I was a kid. I haven't mentioned it but I do have a PSA 2 stage nickel boron trigger in mine.
Also, on the subject of buffers and tubes, I started out fixing my existing buffer system with a Sprinco orange recoil spring coupled with a Kaw Valley 5.6 oz buffer. (2.5" long)This worked well enough and probably would still be in place had I not decided that I wanted to go even heavier. I ordered a 8.5oz XH buffer from Heavybuffers.com along with the recommended Armalite rifle spring. That buffer is 3.25" long and requires the longer 7-5/8" deep tube so I got Armalite kit that I should have gotten much earlier.
I went off on a quest to get the gun to function with or without my suppressor WITHOUT having to change gas settings with an adjustable gas block. My quest was a failure in that regard. Never found that magic balance point where I could do away with adjustable gasblock, but after extensive experimentation I settled on a buffer wt of 7.6 oz. The gun is exceedingly smooth and soft shooting now and so far totally reliable.

If I had to do it over again I would go the Armalite tube and larger buffer route.

 

[Gustav7]

I will say, the Armalite gas tube fits far better around the larger barrel nut used in a Large Frame AR and avoids contact with the barrel nut, some thing most typical Low profile GB and a AR15 gas tube don't do on a Large Frame AR.
Accuracy wise that matters. For those that don't know....You really want a free / easy interaction between the gas tube and gas key.

The shorter Gas tube length hasn't ever seemed to matter in any of mine either. ( DPMS pattern ) All my uppers function 100%
The DPMS pattern gas tube length , while shorter then the Armalite gas tube length, is only part of the gas setup. ( Duh , right ? )

So, according to a few of the more experienced AR308 guys over on the 308ar forum, there was a slight variation in the position of the gas port on the barrel. Supposedly DPMS moved the gas port hole towards the receiver ~1/4" to allow the proper use of the AR15 gas tube. He mentioned that when [X] company tries to make a 308ar they often over look this and can sometimes use the wrong parts or locations. I'm sure that this coupled with some of the buffer issues mixed with mass production has gotten more PA10 issues than "normal".

Some differences....
DPMS BCG's have only 2 exhaust holes in the carrier, restricting flow more then the Armalite 3 gas hole carriers.
While that may sound trivial , it is still a design difference between the 2 patterns.
I think the exhaust port locations are also slightly positioned in different spots on the carrier as well. ( front to back wise )
And that positioning makes for a different volume in the carriers and bolt , between the 2.

This is a very interesting angle I did not previously consider. Good info and something worth noting.

As for other things I would look at....
Extractor, some Toolcraft 308 BCG's can come with a less then precisely cut extractor "claw" .
Make sure the barrel is indexed properly at the barrel extension locating pin into the upper, the feed ramps "should" show obvious out of alignment issues. A poorly indexed barrel extension will result in bolt lug battering.
Make sure simple things are tight... Flash Hider, barrel nut, stuff like that.
Maybe.... consider running it first as it came from the factory ? ... a rapidish fired magazine worth ? ( Obviously check the bore first ) I am curious if it is so lacking in lube to cause malfunctions straight from the box. ( IE , how many people don't clean and relube before firing the firearm and then have function issues )

These are all good ideas. The lower will need assembled so I'll do that first and then just slap it together without any lube and give it a go lol.
See if I can get a mag through it. Then I'll give it some lube based on that and see how it runs.
I'll disassemble the upper from there and inspect everything and take measurements.

IF it runs without serious issue, after taking measurements, I'll probably put ~200 or so rounds through it before I change anything. Provided its not jamming or something is off, I'd like to run it hard and get a feel for how it shoots, both suppressed and unsuppressed. Then I'll add in the upgrades and document changes.

Would you mind linking to the items you bought from PSA ?

No problem. I bought this and their blem stripped lower.
PSA PA10 Rifle "Build Kit"

 

[mtrmn]

Well I don't plan on leaving the stock buffer system on regardless. I'm gonna try it out in the beginning but I'll be putting on the correct Armalite buffer system so I can use standard buffers if I need to adjust weight at all.

Just know that the Armalite system will come with the H3 buffer, which is already the heaviest of the "standard buffers". To go heavier, you'll have to go to something like Heavybuffers.com.

 

[Gustav7]

In keeping with the "low budget" theme with this rifle, I hit up @gr8fuldoug at Camera Land NY and he hooked it up with an open box Burris RT-6 combo w/ the mount and Fastfire 3 for $459 shipped. On top of that, I ordered it Wednesday morning, and I got it today.

I was very tempted to pick up one of the discontinued Steiner P4Xi 1-4x, but I've heard so many good things about the RT-6 for the money, I felt like trying it out. I also have a Fastfire 2 on my .22 pistol, and for the money I really like them, especially on just a fun gun. So even if I don't keep the FF3 on the rifle, I can use it for a .22.

 

[mtrmn]

The lower will need assembled so I'll do that first and then just slap it together without any lube and give it a go lol.

I hope the lol means you're joking. Break it in dripping with oil please.

 

[Gustav7]

I hope the lol means you're joking. Break it in dripping with oil please.

Haha, it was @bfoosh006 idea. And I was only going to do a mag, if that, to see if it would run. I promise I'm not going to pull a T-rex Arms and try to run 5000 rounds through it without lube. It'll be dripping in Rotella T6 after the 2nd mag.

 

[bfoosh006]

I'm sure that this coupled with some of the buffer issues mixed with mass production has gotten more PA10 issues than "normal".

Omg... I kinda forgot about that issue. It happened so often that I couldn't help but wonder if some assemblers ( or one ) was doing it on purpose !

 

[mtrmn]

So, according to a few of the more experienced AR308 guys over on the 308ar forum, there was a slight variation in the position of the gas port on the barrel. Supposedly DPMS moved the gas port hole towards the receiver ~1/4" to allow the proper use of the AR15 gas tube. He mentioned that when [X] company tries to make a 308ar they often over look this and can sometimes use the wrong parts or locations. I'm sure that this coupled with some of the buffer issues mixed with mass production has gotten more PA10 issues than "normal".

Yes, this was my issue when I ditched the heavy PSA bbl for the Faxon pencil barrel. The Faxon came with the "Armalite AR10 carbine" spacing rather than the "PSA AR15 midlength" spacing, which made my "midlength" gas tube too short by 5/16". The Armalite tubes were out of stock everywhere at the time but I found one by LBE that was correct.
The tubes designed from the get-go for a 308 also have the proper bends to get the proper clearance above the barrel/barrel nut and insures they enter the gas key at the proper angle.

 

[bfoosh006]

Haha, it was @bfoosh006 idea. And I was only going to do a mag, if that, to see if it would run. I promise I'm not going to pull a T-rex Arms and try to run 5000 rounds through it without lube. It'll be dripping in Rotella T6 after the 2nd mag.

It was my idea, I have always wondered if a PSA would run as is from the factory... and yes Lol.

And mtrmn is 100% correct Large Frame AR's should be broken in with plenty of lube.

However... I never considered it for any of the PSA uppers I bought.

And while it sounds foolish, I do still wonder if a inexpensive PSA upper could do it.

And If Gustav7 doesn't want to do it, I have no problem with that. But given it is a new upper, that would be the least broken in PSA upper I have seen tested.


Oooof... While writing this , it just dawned on me I have a Virgin 20" 308 PSA Nitrited barrel complete upper in storage.
Untouched , except stored in VCI and a VCI tube down the bore !

So my apologies, I will do it to my own upper. Thanks for considering it though.


And the link for the 308 kit doesn't seem to be working for me. I assume it is this one ?

https://palmettostatearmory.com/psa...l-15-lightweight-m-lok-moe-ept-rifle-kit.html

Gustav7, if you need comparisons of OEM PSA PA10 / 65 parts let me know, I am one of those guys that stock piles spare parts for all my firearms

 

[mtrmn]

On the adjustable gas block issue:
I went from a Seekins low profile adjustable that I had to count the number of rounds I turned the adjustment screw (starting from the fully closed position) to the Seekins select gas block (linked below). This one has a throw lever you can lock down on the adjustment screw and then flip it from one side to the other depending on whether you have the suppressor installed or not. Greatly simplified the adjustment debacle and eliminated having to keep up with Allen wrenches etc in the field. I found mine at my local gun store.

Select Adjustable Gas Block

Select Adjustable Gas Block The addition of a suppressor, dirty conditions or even switching ammo are all factors that can lead to undesirable gas settings on your rifle. Our patented design was developed, tested, and fielded by Special Operations who

seekinsprecision.com

 

[Gustav7]

And the link for the 308 kit doesn't seem to be working for me. I assume it is this one ?

https://palmettostatearmory.com/psa...l-15-lightweight-m-lok-moe-ept-rifle-kit.html

Gustav7, if you need comparisons of OEM PSA PA10 / 65 parts let me know, I am one of those guys that stock piles spare parts for all my firearms

Thats the one. Appreciate it, I'll let you know.

 

[Steve_In_29]

FWIW... I have several PSA Large Frames and Uppers with various gas system lengths, barrel lengths, and calibers, and ultimately the buffer system ( DPMS carbine pattern and Armalite carbine pattern ) have all worked as intended.

My following comments aren't intended as strictly directed to the OP, but for others reading as well.

So please don't take this personal OP , just some of my observations.

I do think the Armalite pattern is a more versatile pattern only because it uses a more commonly available 3.25" buffer length.
FWIW, anyone can buy a DPMS pattern 2.5" buffer in a 5.3oz weight... but most current 2.5" buffers ( again DPMS carbine pattern ) from various manufacturers ( Aero, and PSA being 2 of the more common places ) come lighter then a typical Armalite 3.25" buffer.

DPMS also "wanted" to use as many AR15 parts as possible, IE gas tubes, buffer tubes. ( less expensive route ? really not sure why )
Armalite "wanted" to build a scaled up Large Frame AR, and took the time to develop scaled up parts as well, buffer weight included.

I will say, the Armalite gas tube fits far better around the larger barrel nut used in a Large Frame AR and avoids contact with the barrel nut, some thing most typical Low profile GB and a AR15 gas tube don't do on a Large Frame AR.
Accuracy wise that matters. For those that don't know....You really want a free / easy interaction between the gas tube and gas key.

That said the shorter DPMS pattern buffer setup has been used successfully in God knows how many Large Frames over the years. ( same can be said about the Armalite pattern )

The shorter Gas tube length hasn't ever seemed to matter in any of mine either. ( DPMS pattern ) All my uppers function 100%
The DPMS pattern gas tube length , while shorter then the Armalite gas tube length, is only part of the gas setup. ( Duh , right ? )

Some differences....
DPMS BCG's have only 2 exhaust holes in the carrier, restricting flow more then the Armalite 3 gas hole carriers.
While that may sound trivial , it is still a design difference between the 2 patterns.
I think the exhaust port locations are also slightly positioned in different spots on the carrier as well. ( front to back wise )
And that positioning makes for a different volume in the carriers and bolt , between the 2.
So while a Armalite longer gas tube makes for a "longer" pressure push, it is also bleeding out gas faster than the shorter DPMS gas tube and its 2 exhaust ports.

All this is just semantics, between the 2 patterns, since both systems obviously work.

Kind of a Ford v. Chevy thing.

If one or the other didn't work, the non working pattern would have died off.
There are other subtle differences between the 2 BCG's as well. I have that info at home and will post later.


The 1 thing that I have noticed , that made the most difference in function, was the gas port size.

"Almost" Every DPMS pattern barrel, length, gas system length and brand, was over gassed. The gas ports are just to big.
My Krieger is the only barrel I have that has a "correct" ( ? ) gas port size. Maybe better said, a smaller gas port size would help.
Every other barrel length / gas length / brand has benefited from an Adj. GB, in numerous ways, function being the #1.

I realize a large gas port allows for 100% reliable function under adverse conditions ( etc. ) ... but it also led to the cyclic speed in my PSA's being so high that it would cause odd issues. ( Again various brand barrels, with large gas ports PSA included. )
"Short stroking" is one of those3 issues ... but IMHO that is more a result of a gas port being to big , causing the cyclic speed to out run some of the other parts , and bouncing the buffer off the bottom of the buffer tube.

The Gen II PSA's were a great example of how little it took to throw "off" the cycling of a Large Frame AR.
The Gen II's were known for the BCG smacking the the threads on the lower at the buffer tube, and battering those threads, that alone would jack up function almost everytime.
I say almost because none of mine ever did it , but there are numerous reports on the various forums.

Current Gen III lowers have cutouts at the Gen II impact points, and that fixed that issue.


As for other things I would look at....

Extractor, some Toolcraft 308 BCG's can come with a less then precisely cut extractor "claw" .

Make sure the barrel is indexed properly at the barrel extension locating pin into the upper, the feed ramps "should" show obvious out of alignment issues. A poorly indexed barrel extension will result in bolt lug battering. ( Another member had one that was way out of clock, and it beat the hell out of the bolt locking lugs, heck the alignment locating pin freely fell out of the barrel extension )

Make sure simple things are tight... Flash Hider, barrel nut, stuff like that.

Maybe.... consider running it first as it came from the factory ? ... a rapidish fired magazine worth ? ( Obviously check the bore first ) I am curious if it is so lacking in lube to cause malfunctions straight from the box. ( IE , how many people don't clean and relube before firing the firearm and then have function issues )


Would you mind linking to the items you bought from PSA ?


All this said, I am looking forward to your accuracy results, measurements, etc.

Both my PA10s (rifle length) have the slightly shorter gas tube and they work fine as well.

 

[gopherslayer]

It was my idea, I have always wondered if a PSA would run as is from the factory... and yes Lol.

And mtrmn is 100% correct Large Frame AR's should be broken in with plenty of lube.

However... I never considered it for any of the PSA uppers I bought.

And while it sounds foolish, I do still wonder if a inexpensive PSA upper could do it.

And If Gustav7 doesn't want to do it, I have no problem with that. But given it is a new upper, that would be the least broken in PSA upper I have seen tested.


Oooof... While writing this , it just dawned on me I have a Virgin 20" 308 PSA Nitrited barrel complete upper in storage.
Untouched , except stored in VCI and a VCI tube down the bore !

So my apologies, I will do it to my own upper. Thanks for considering it though.


And the link for the 308 kit doesn't seem to be working for me. I assume it is this one ?

https://palmettostatearmory.com/psa...l-15-lightweight-m-lok-moe-ept-rifle-kit.html

Gustav7, if you need comparisons of OEM PSA PA10 / 65 parts let me know, I am one of those guys that stock piles spare parts for all my firearms

I promptly put 40 rounds down my PSA with just looking down the bore and didn’t lube it. Went home and applied a little CLP and went hunting. It’s my loaner rifle these days. Nobody has asked to borrow a rifle since they found out it was the loaner now. Elmer likes a bolt gun I guess.

 

[AccuSol-ERN]

A ton of guys talk shit on PSAs large and small ARs......but I find them to be great for bullet hose ARs. I've yet to have one not be acceptable and have a few that suprised me how well they shoot.

If I need to grab a superbly accurate rifle.......its never going to be a gasser anyway.

Ern

 

[Gustav7]

***UPDATE***​

Got the upper and lower build kit in. Lower build kit looks normal, we'll see how it all goes together.

The complete upper weighed in at 5lbs 11oz. Overall, it looks fine, no serious fit or finish issues, especially given the price. BCG and bolt were lightly oiled in the typical "mechanic shop" smelling oil. No real lube of any kind. Bore was clean and smooth.

According to the little card they give you with the AGB wrench, my gas block had 26 clicks, and therefore was a 5 position gas block. If it had 17 clicks, it would be a 3 position. Not sure how that works that way, but whatever. Adjustment screw seems chincy and the "clicks" are very light and barely audible. Gas block was positioned perfectly over the gas port. The gas port ended up being ~0.077". I'm assuming the fact that its midlength gas on an 18" barrel with a cheap buffer system warranted the smaller gas port. We'll see how it runs.
Gas tube was the standard AR midlength at ~11.75" and stops just past the start of the cam pin cutout. For anyone looking for possibly higher reliability, the Armalite tube might be a better option at ~1/4" longer.

The M.I. rail is not bad at all. Nothing like an SLR but useable for me anyways. Has anti rotation tabs at the top, lined up close to perfect. There were only 2/3 screws in the mounting portion, but it did have the internal screw that runs in the channel of the barrel nut. All screws were dry.

Bolt had brass on it, I'm assuming from test firing...or I received a used/returned bolt LOL. Ejector looked fine, no serious sharp edges. Extractor looked fine to me. It had the outer and inner spring with the rubber gasket as well. Seems like overkill, but we'll see. Gas rings on bolt seem fine and were separated. Firing pin seemed to have a good fit.

Feed Ramps lined up, although they don't look perfect. Did not seem to effect bolt closure but we'll see tomorrow. I'm heading up to Rubber City Armory tomorrow (its 90min from me) to talk to Jeff Larson up there. We have been emailing back and forth and he's going to headspace the bolt and also try out a RCA bolt and BCG to see how it fits and if it headspaces better or worse. Provided its fine, I will most likely pick up a full BCG from him to have an extra, but also because he has been awesome to talk to and very informative and welcoming. Great guy/company.

The carbine buffer I got with the kit is standard 7". Spring is standard and honestly looks/feels cheap. Compared to the Armalite spring that feels/looks more like a high quality Sprinco. You can also see its over 2" longer, even though the buffer tube is only ~3/4" longer. I really feel like Armalite did the buffer and spring assembly this way for a reason. After initial testing, I'll be switching over and seeing how it effects recoil and shootability. Superior build quality of the Armalite tube over the carbine tube is obvious (AR on the left, PSA on right). Buffers weighed the respective standard; 5.4oz for the Armalite H3, and 3.8oz for the PSA shorty.

That's it for now. I'm excited to see Rubber City Armory's facility and talk to Jeff about BCG's and how they operate, as well as their adjustable gas key and nitriding process. If anyone can think of something they'd want to know about RCA's BCG's lemme know and I'll ask.

 

[mtrmn]

Excellent pictorial history of this project so far. None of mine are anywhere near this nice and thorough.
If you're going to use the PSA bolt, I suggest rounding off that ejector a lot more than it is presently. If you find pics of other "enhanced" bolts, a lot of the ejectors will be completely round on the end. When a round feeds from the right side of the mag, it tends to "slide" across the surface of the ejector and any sharp edge may gouge out the brass. It will also look like an "ejector swipe" when actually no such thing is taking place leading to false signs of overgassing. I removed my ejectors and chucked them in a drill. Held them at varying angles against a cheap sharpening stone while spinning in the drill to create a rounded tip. Just don't shorten the length.

 

[Gustav7]

Excellent pictorial history of this project so far. None of mine are anywhere near this nice and thorough.
If you're going to use the PSA bolt, I suggest rounding off that ejector a lot more than it is presently. If you find pics of other "enhanced" bolts, a lot of the ejectors will be completely round on the end. When a round feeds from the right side of the mag, it tends to "slide" across the surface of the ejector and any sharp edge may gouge out the brass. It will also look like an "ejector swipe" when actually no such thing is taking place leading to false signs of overgassing. I removed my ejectors and chucked them in a drill. Held them at varying angles against a cheap sharpening stone while spinning in the drill to create a rounded tip. Just don't shorten the length.

That’s a good idea. It was by no means sharp, but I could easily see improvement for sure. There were also brass shavings on it from test firing so I’m assuming you’re right.

Thanks, just trying to be more like @Molon

 

[mtrmn]

Thanks, just trying to be more like @Molon

I admire your aspirations

 

[bfoosh006]

Great info ! Thanks for taking the time to post all the photos and info.

Sending you an IM.

And you are spot on about the PSA buffer and recoil spring being "bargain priced" Lol.
I ended up using a 308 Tubbs Flatwire in my DPMS pattern carbine stocks, and a 5.3oz KAK 2.5" buffer.
I still think the Tubbs and 2.5" is what "probably" helped my Gen II's avoid the battering others experienced at the 2017'ish timeframe.

BTW, how smooth was the inside of the OEM PSA buffer tube ? And while on the subject how smooth is the Armalite buffer tube interior ?

 

[Steve_In_29]

That's where the gas tube stops on both of mine and no issues so far.

 

[mtrmn]

Looking at the feed ramps they will most likely never give any problems. However, the point in the ramps where the upper receiver transitions to the barrel extension looks to have a slight upset creating a potential sharp edge in the ramp. IF you see copper jacket material in this area, you may have to do some very careful polishing of those edges but the only ones I've seen give trouble were much worse than yours.

 

[Gustav7]

And you are spot on about the PSA buffer and recoil spring being "bargain priced" Lol.
I ended up using a 308 Tubbs Flatwire in my DPMS pattern carbine stocks, and a 5.3oz KAK 2.5" buffer.
I still think the Tubbs and 2.5" is what "probably" helped my Gen II's avoid the battering others experienced at the 2017'ish timeframe.
BTW, how smooth was the inside of the OEM PSA buffer tube ? And while on the subject how smooth is the Armalite buffer tube interior ?

I would imagine so. I showed Jeff at Rubber City Armory the carbine buffer spring and his eyes got wide, he turned around and showed me what he/they use, and you could easily see and feel the difference in strength and thickness of the spring. The new lowers they use have "cutouts" in the lower ear are by the RE, which now sounds like a cover up for cheap buffer components lol.

I didn't think to check the quality of the inside of the buffer, so good idea, and its also very noticeable. The inside of the PSA looks and feels like it was drilled out with a dewalt. The bottom also has what looks like a crack, or chipping. The Armalite tube is smooth as glass and shiny. The bottom looks like a perfectly milled out bottom thats shiny and symmetric but shows the mill/finish marks.

I talked with Jeff Larson, who I found out is the Operations Manager for Rubber City Armory. What I didn't know is they have one of the largest Salt Bath Nitride facilities in Florida and they Nitride most of the BCG/Bolts for Toolcraft and PSA. He was very nice and informative and he ran through the whole BCG and bolt, checked headspace, a few other little homemade tests. He said it all looked good functionality wise, but noted the same thing about the ejector and just to watch it.
He compared one of their carriers to the PSA and the only main difference was a few corners cut with machining and finish work. He said it shouldn't harm function, but is most likely one way they save a few coins over thousands of carriers.

 

[mtrmn]

I would imagine so. I showed Jeff at Rubber City Armory the carbine buffer spring and his eyes got wide, he turned around and showed me what he/they use, and you could easily see and feel the difference in strength and thickness of the spring. The new lowers they use have "cutouts" in the lower ear are by the RE, which now sounds like a cover up for cheap buffer components lol.

I didn't think to check the quality of the inside of the buffer, so good idea, and its also very noticeable. The inside of the PSA looks and feels like it was drilled out with a dewalt. The bottom also has what looks like a crack, or chipping. The Armalite tube is smooth as glass and shiny. The bottom looks like a perfectly milled out bottom thats shiny and symmetric but shows the mill/finish marks.
View attachment 8064337View attachment 8064338



I talked with Jeff Larson, who I found out is the Operations Manager for Rubber City Armory. What I didn't know is they have one of the largest Salt Bath Nitride facilities in Florida and they Nitride most of the BCG/Bolts for Toolcraft and PSA. He was very nice and informative and he ran through the whole BCG and bolt, checked headspace, a few other little homemade tests. He said it all looked good functionality wise, but noted the same thing about the ejector and just to watch it.
He compared one of their carriers to the PSA and the only main difference was a few corners cut with machining and finish work. He said it shouldn't harm function, but is most likely one way they save a few coins over thousands of carriers.

I've been told not to trust my lying eyes, but the PSA on the left looks a little off-center on the bore.

 

[Gustav7]

I've been told not to trust my lying eyes, but the PSA on the left looks a little off-center on the bore.

This isnt just a guess, but also isn't verified, but some guys think, and rightly so, that PSA has those bored low on the bottom side to avoid carrier tilt issues.

When you assemble a cheap LR308 without the more agreed upon variations, you get issue. Carriers hitting buffer tubes both on the bottom and the smashing into the rear because you used shit springs and light buffers. Carriers hitting the lower ears on the receiver due to the same issues. Adjusting gas port size and location to save money on proper buffers and cover up your other cut corners. Now obviously some guns run fine, but my guess is they could run better if they utilized better parts.

Comparing the two buffer tubes made me realize just how good of a decision the Armalite set up is. I'm also thinking longevity. The PSA stock may run fine, but how long will it last? Changing to a few better parts may reduce recoil, and keep it running much longer.

 

[BCP]

Could just be how it was machined near the threaded/notched part, the feedramps you can "polish" with a dremel.

 

[bfoosh006]

"Carriers hitting the lower ears on the receiver due to the same issues."

FWIW, That actually has a lot to do with how the carrier is cut at those contact areas as well, some of the various brand carriers used, have a sharp corner there, other brand carriers are recessed ( ? ) more rounded area there.
PSA has used both style BCG's , and frankly, the PSA fix worked quite well. Simple and effective.

I would like to see the difference in a Aero Precision 308 DPMS pattern carbine recoil spring and a PSA one , and I am pretty sure Aero uses the same 2.5" buffer weight of 3.8oz.
I wonder if the Aero and PSA carbine recoil springs are made by the same company, to the same spec.

I am glad to see the Armalite buffer tube is smoother inside, since it costs darn near twice as much, and it is good to see the price isn't just for the name.
I have bought other "name brand" buffer tubes looking for a smooth interior, and quite a few were dubious inside, I could feel the ridges, with my finger tip ! So good to know Armalite is another smooth one.

Also and another FWIW, PSA did at one point use the same Vltor / Armalite length buffer tube and 3.25" buffer ... but for whatever reason they abandoned it.
Probably a cost saving measure, just like DPMS and Aero did.

BTW, did Armalite quit selling parts on their webpage ? Sure seems odd I don't see any on there. I know they used to.

I haven't heard of any PSA buffer tube failing, and again ( FWIW ) mine have run many thousands of rounds.
Then again I do run a 5.3oz 2.5" and the Tubbs with an adj GB.

So no meaningful input on the PSA recoil spring, since I changed mine soon after buying mine, just to slow the bolt unlocking so soon. I wish I had just moved to a Adj GB from the get go, Lol

I also see the PSA tube is made from 7075, ( GI spec material ) and not some cheaper material. ( Just went and looked )

I'd bet 6061 would work, but... I would prefer 7075.

I guess I haven't noticed, but is the PSA drain hole really that much smaller then the Armalites ?

"This isnt just a guess, but also isn't verified, but some guys think, and rightly so, that PSA has those bored low on the bottom side to avoid carrier tilt issues."

Are you saying PSA might have a carrier tilt issue ? That is the first time I have heard that.
Would that apply to the AR15 model as well ? It is the same buffer tube.

Where did you hear this ?

I'll measure my buffer tubes, I can't say I have ever noticed any of them being off center, both on AR15's and PA10's

Anyhow, thanks for the updates

 

[mtrmn]

BTW, did Armalite quit selling parts on their webpage ? Sure seems odd I don't see any on there. I know they used to.

I was on their site less than 3 weeks ago and all the parts were there. Just went and looked and no parts to be found anywhere on the site. I don't know how many times the Armalite brand has changed hands, but it appears TO ME the present ownership may be struggling.(?) I know their parts have gone in/out of stock very frequently lately, and every time I have needed to order for myself they were always out, driving me to search elsewhere. Of course it's not like I was ordering something every week lol.