This is substantially the same comments I posted in the reviews on the Palmetto website. They turn whatever you write into a wall of text. So, I'm explicating and formatting here.

TLDR version:
1. Palmetto extractor assembly is junk. Replace extractor assembly.
2. Feed ramps may look like they were "fitted" by angry monkey.
3. Gas tube is abnormally short.
4. Accuracy was quite good once failure-to-eject issue was cured.

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I purchased a Palmetto PA-10 complete rifle-length upper in February 2019. The upper is now mounted on a correctly-functioning PA-10 lower purchased at the same time frame.

I have three criticisms of the PA-10 rifle-length upper.

1.The upper would not reliably EJECT spent cases. About 50% failure rate. The rifle would fire, and it would leave the spent case sitting on top of the magazine follower. If there were additional rounds in the magazine, the un-ejected case would get “jammed” with the next round. I determined the cause of the failure-to-eject to be a defective extractor spring. Palmetto uses a pair of springs for the PA-10 extractor. A small spring inside of a counter-wound larger spring. The pair of Palmetto springs provide significantly weaker tension on the extractor than the extractor-springs furnished by other vendors. I was not satisfied either with the size of the claw on the Palmetto extractor. The Palmetto claw was narrower than the claw on extractors offered by other AR-10 parts vendors. I replaced the Palmetto extractor springs with a spring set (one coil spring and one polymer reinforcement-stem and one O-ring), and also the extractor itself, from another vendor. Replacement of the entire extractor assembly with parts from another vendor cured the failure-to-extract problem. I subtracted a star in the rating because of this.

2.The feed-ramp on the barrel extension was severely rough-textured due to the obvious use of a coarse-stone grinder-tool on the ramps. We can only wonder why Palmetto used such a coarse, and imprecise, tool on the ramps. The cuts were rough and irregular-symmetry. At least the grinder-operator could have given the ramps a little attention with some sandpaper. The ramps were so rough that the burrs on the ramp would tear cotton off a cotton swab if a swab was used to clean the area. Before firing the rifle, I had to file and sand the rough ramps to prevent the ramps from abrading the bullet-tip as the cartridges were fed into the chamber. I subtracted another star in the rating because of this.

3.The gas tube used by Palmetto in this upper is shorter than commonly found in rifle-length AR-10 type uppers. The shorter Palmetto tube extends a shorter-than-usual distance into the “key” on the bolt carrier. I replaced the Palmetto tube with a tube, from another vendor, which measures the typical 15.5”. I am not prepared to say that the shorter Palmetto tube contributed to the failure-to-eject problems. However, the Palmetto gas tube length is an irregularity that I chose to correct as I was diagnosing the failure-to-eject problem. Because the shorter tube may actually function OK (which I cannot say one way or the other) I did not subtract a star from the rating because of the unusually-short gas tube.

Once the failure-to-eject issue was solved, I was able to test the upper for accuracy. I installed the upper on the Palmetto complete PA-10 lower, but with modifications to the complete lower. I added an expensive aftermarket trigger from another vendor, and I added an expensive aftermarket buttstock from another vendor. So-configured, the Palmetto upper delivered very acceptable accuracy.

I have attached photos to this review to illustrate my comments.

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PA-10 compared to AR-15

Palmetto extractor assembly

3 moa; correct?

Palmetto extractor compared to Fulton Armory extractor.

Note that claw on Palmetto part is narrower than claw on Fulton part.

Prone.

Sling support only.

Unfamiliar rifle.

The two high shots felt a little weird when I sent them. If that means anything to you.

Gas tube comparison.

Longer tube is the "normal" 15.5" used by other vendors for "rifle-length" application.

As mentioned above, if the rifle was loaded with only a single round, half the time the spent case never left the rifle. Just got deposited on top of the mag-follower.

If more than one round was loaded into the rifle, spent brass (and a mis-fed live round) had to be wrestled out of the rifle most of the time. Spent brass was usually slammed back into the teeth of the barrel extension.

As someone who's built two PA-10's (one G1, one G2), there a few things to note here.

1) non AR10 (armalite) 308 AR's (such as DPMS based, which is what the PA series is), the gas tube does not meet in the middle cutout, as your typical AR does (your "replacement" gas tube is too long (passes mid mark) and could/will cause interference/binding with the gas tube). The gas tube on these (or any DPMS based) typically reaches 1/4 into the scallop (not halfway, and certainly not past halfway, where yours is now). When people use a "longer" (this is often an AR10, Armalite, gas tube, which run about 1/2" longer) in a DPMS pattern, they'll experience binding/bending of the gas tube (or occasional not fully seated bcg) from such (yeah, I made that mistake with my first build). They differ (DPMS vs Armalite) because they both use different distance specs for the gas port hole. The gas tube that PSA had in it is the correct one for this (DPMS pattern) rifle.

2) If your brass was pulling back onto the magazine, the extractor did it's job. The ejector is what failed (and binding ejectors has been a common complaint on PA-10's, although I've not experienced that issue). They are also no consistent with their extractor set ups (some have dual springs, some have single + Oring, some just single spring, etc. They use different vendors, who do it differently. I always ditch everything but ONE spring (a properly tuned 308 doesn't need a herculean spring. All that does is beat up your brass rims).

3) feedramps are meh. Mine aren't the prettiest, either, but they work (and are no more ugly than most of my AR's).

And I'll add:
4) (of my own) The BIGGEST issue with PA-10's is bolt carrier "timing". Simply, PSA doesn't do it. The user must do it. If your bolt face goes further than 3/16" past the bolt catch... you're going to have issues (bcg/receiver impact, eventual broken bolt catch, etc). BOTH of mine needed at least one quarter placed behind the recoil spring to push the bolt face to between 1/8-3/16 overtravel past the bolt catch. A 308 WILL compress the heck out of a buffer bumper, so that has to be taken into account (thus the NO longer than 3/16" past, with 1/8" being optimal).
Also (IMO) an adjustable gas block is a must with any 308 AR, since 308 ammo varies MUCH more wildly than 5.56. Being able to run anything (properly) is easy with an adjustable gas block. My pick for both of mine were SLR Sentry-7's.

PA-10's are FUN to build (or buy), but like with most 308 AR's, they need some tweaking.

My (ETA: apparently flipped upside down by Tinypic?) PA-10 (G2) with 16" mid length Faxon pencil barrel, VG6 comp and Odin handguard:


EDIT: I stand corrected (just checked)…. I DID in fact leave one o-ring in the extractor assemblies. Mine came with a ridiculous set up (main spring, DOUBLE O-rings, AND spring insert ).
I removed all but the main spring, and one O-ring. Works like a champ (now. It would not let go of the brass with their ridiculous set up).

@ MaverickAA

I very well understand the different mechanical roles of the extractor and the ejector.

The Palmetto ejector is still in the Palmetto bolt.

The Palmetto ejector has lots of spring-tension. No sign of improper friction or improper position or improper axis of movement.

The rifle would not expel the spent case with the Palmetto extractor assembly in place. I replaced the Palmetto extractor assembly with an assembly from Fulton Armory. The rifle now expels the spent cases with authority.

The longer gas tube appears to be for the Armalite AR-10 while the shorter is for a 5.56 AR.  A subtle but distinct quarter-inch.

This is correct.

I own a DPMS LR-308T (16" factory gun).

Here is a pic of how far the head of the gas tube extends in that gun.

To reiterate what Maverick said the ArmaLite AR10 gas tube is longer.  That's because ArmaLite puts the gas port another 1/4 inch farther out on their barrels than the others.  They did this so they could use A1/A2 handguards with the bigger AR10 barrel nut, and delta ring.  Here is a picture of an ArmaLite built AR10 upper showing the location of the end of the gas tube.



There is also a difference in where the gas keys and exhaust ports are positioned between the ArmaLite BCG and the DPMS style (PSA)



The ArmaLite one (top) sits about 3/32 further back.



More gas ports on the ArmaLite and further forward.

If your rifle is working, OK but 1; you maybe could wring out a little more accuracy with a slightly shorter gas tube if there is interference.  I was going to say It looks like the gas tube should be half way between those two,  2; it could be your rifle is a tad over gassed with the DPMS style BCG and that longer ArmaLite gas tube on a barrel made for a DPMS rifle.

@ Earlosammich

That is very interesting and useful information. Thank you.

Looks like both of my reviews on the Palmetto site are still squashed.

Palmetto sent me a reply via email.

It’s not uncommon (with PA-10) for the ejector to initially bind up, then free itself. If it were your extractor that was failing, your cases would not have been pulled out of the chamber.

I don't know about that Maverick.  When ArmaLites AR10s first came out I had this exact issue with my first one.  Their fix was the polymer dimple and rubber "O" ring under the extractor.  Seems the sometimes violent extraction let the case trip out from under the extractor.  As the bolt heads rear the case is pushed to the right in the barrel extension and the extractor can lose it's grip.  I had this issue and the extra spring tension under the extractor fixed it.  I also "tuned" my ejector/ejector spring so I didn't have to chase brass into the next time zone.

@W.E.G.  Can you post up some pics of your brass, please.  The case head looking for a swipe mark from the ejector and the case rim looking for a swipe mark from the extractor.

Good info in the thread.  I just traded for a used PA10 last week.  Mine is a 16 inch stainless.  From the looks of the bolt tail it seems to have not been fired.  Last Friday I ran 60 rounds of 168 gr Remington and 20 rounds of 168 gr Hornady TAP through it.  I had three malfunctions with the Remington ammo.  First two mags through the gun with 10 round Pmags the second to last round did not eject and I got a double feed with both mags.  I took the double o rings off the extractor spring and went through a few more mags and they emptied and locked back.  Probably between rounds 50 and 60 I had a round not extract at all.  So I wondered if taking the o rings off reduced the extractor tension to much.  My last box was Hornady TAP.  It seemed hotter than the Remington and all twenty rounds ran fine.  I've ordered a KAK 5.3 oz buffer to replace the 2.5 inch 3.7 oz factory buffer.  I'm hoping after running a few hundred rounds through the rifle all the bugs will work out.

WES I'm right down the street from you.  We'll have to go shooting sometime.  David

Very interesting to hear your updates about the PA-10. I have tinkered with 308 AR's for a long time - I built 2 from scratch several years ago before the relative explosion in the large-frame AR market. They have always been more finicky.

This thread touches on some very important points.
1. Consistent extraction/ejection is not just about more extractor tension. There is a balance between extractor tension and ejector pressure to grab the case, extract it, and then fling it out. I had one 308 AR that I put together that just wouldn't eject. Turned out the extractor spring was actually TOO strong, and ejector too weak, such that the cases wouldn't reliably clear the ejection port. This was cured by removal of the extractor o-ring, and a stronger ejector spring. I bet the issue with yours was binding that was overcome by the stronger spring.

MOST notably - I have never had SINGLE malfunction in any of the rifles I put a JP 308 bolt in, and it fixed another one immediately. It also really seems to help reliability with short cases like the 6.5 Creedmoor.

2. I only have DPMS pattern rifles, and all of them have the gas tube that sticks further into the upper. This includes SI Defense, DPMS LR-308, and PA-10. I have had no issues directly related to the gas tube.

3. Totally agree on necessity to check how far the BCG over-runs the bolt catch. 1/8" is about perfect. Before I figured this out, I broke 2 bolt catches in my SI Defense build.

4. Both of my PA-10's did not have the reliability issues that yours did. They eat everything. One is a 18" mid-length, the other is an 18" rifle gas CHF.

Hmm. I haven't heard of that, But I guess it's possible.

I fired the PA-10 again today.

About 20 rounds. No function problems at all.

I will post some pics of my spent brass soon, as time and opportunity presents.

We are hosting highpower rifle matches at Fairfax Rod and Gun Club on Saturday and Sunday this weekend.

Muster at 0800 for squadding on the Benson range. Hot-time is 0900. Cold-time probably around 1400.

200 yards - 50 shots for record (20 offhand, 10 RF sitting, 10 RF prone, 10 slow-fire prone).

NRA rules: http://rulebooks.nra.org/documents/pdf/compete/RuleBooks/HPR/2018-hpr-book.pdf

I think match entry fee is $15/day.

7039 Signal Hill Road Manassas VA 20111

You will need a gate-code to enter unless you can piggy-back behind another driver.
Message me for the gate code for this weekend.

Compilation/Comparison in case anybody is interested.

Pics of the spent brass were requested. I believe the idea is to inspect the bases and rims of the cases for evidence of unusual interaction of the extractor and the brass. The most serious sorts of unusual interaction typically is severely-bent case rims. There is no evidence of bent case rims in any of the pics that follow. Except for the smashed case mouths on the cases that were not expelled from the rifle while the Palmetto extractor assembly was in-play, all the brass is unremarkable in my estimation.

The PALMETTO bolt was used for firing each batch of brass. The only thing that changed on the rifle between batches of brass was replacement of the extractor assembly with a Fulton Armory extractor assembly (claw, spring, polymer insert).

The images that follow are three batches of brass.

FIRST BATCH
This brass is Santa Barbara (Spanish) surplus ammo fresh from the factory box.
Two pics of brass fired with the Palmetto extractor assembly.
Each of these pieces of brass failed to be expelled from the rifle, and each was jammed back into the barrel extension, as the rifle tried to feed the next round from the magazine.
You can see the case-mouth of each piece is damaged from slamming back into the barrel-extension (“locking lugs”).





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SECOND BATCH
This brass is Santa Barbara (Spanish) surplus ammo fresh from the factory box.
Three pics of brass fired with the Fulton extractor assembly.
Each of these cases was expelled normally during firing/cycling.







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THIRD BATCH
This brass is Lake City Match (M-852) on its third firing.
Three pics of brass fired with the Fulton extractor assembly.
Each of these cases was expelled normally during firing/cycling.

In view of the claw-mark on the rims of each respective lot of cases, I guess it would be accurate to describe the claw-mark from the PALMETTO extractor as being less-pronounced than the claw-mark from the Fulton extractor.

I don't find this at all suprising, as the major issue that is the topic of this thread is the failure of the PALMETTO extractor to function sufficiently that the cases could be expelled from the rifle during cycling.

Well crap,  ow I have some questions on my own two builds.  I have two complete PSA PA-10 uppers and two ballistic Advantage barrels, a mid length gas and rifle length gas system.  What gas tubes do I use then? Regular ar-15 gas tubes or do I have to use other ones?

I have no firm opinion on whether the shorter tube used by Palmetto is good-to-go or otherwise.

If it works, I guess its not stupid. I'm going to try to get some more evidence on the range using a couple more configurations, and I will report as progress is made.

Yeah.  LOL.

My PA-10

Mine had claw marks, bent rims, blown primers, and ejector hole displacement.  My PA-10 was severely over gassed.  16" mid length gas.

PSA won't give much of a fuck about posting on their forum.  They will want you to send in your rifle.

This thread has presented my concern about the PALMETTO gas tube.

Particularly, the issue is whether the PALMETTO gas tube extends far enough into the gas key to ensure that the rifle will cycle properly.

This raises the question of: What is the maximum distance a gas tube can extend into a gas key before the tube is too far into the gas key?

I had a tube sitting on the bench, so I inserted the tube into the PA-10 carrier until the head of the tube bottomed-out inside the gas key. Then, I marked the tube with blue tape to indicate the spot at which maximum insertion occurred.



Conceding that my measurement may be off by one or two thousandths, I’m going to say that the maximum depth is 0.831”.



Now, seeing as how I replaced the PALMETTO gas tube, due to my concern that it appeared short, the next question is: Is the 15.5” Fulton tube too long? I’m going to answer that right now by saying the Fulton tube is not too long. The Fulton tube does not bottom-out against the gas tube when the bolt/carrier assembly is installed. Moreover, it appears to me that the Fulton gas tube installs well short of the point where it might bottom-out inside the gas key.

All this begs the question: What is the correct depth of insertion for the gas tube into the gas key? One school of thought would say the insertion is correct if the rifle cycles. Another school of thought might say there is a range of acceptable insertion. I’m going to be completely candid, and admit I do not know the answer to this question.

A related question is: Does the depth of insertion of the gas tube relate to the amount of felt-recoil by the shooter? Again I don’t know the answer to this question. As time permits, I may re-install the shorter PALMETTO gas tube in conjunction with the PALMETTO bolt equipped with the Fulton Armory extractor assembly, and see if I can tell any difference in the felt-recoil of the shorter tube versus the longer tube. I am of the unverified opinion that so long as the buffer isn’t bottoming-out inside the buffer tube (“receiver extension”) during firing, the shooter is unlikely to notice any significant difference in felt recoil of one gas tube versus another.

So, back to the measurements. From a visual standpoint, how far would a gas tube need to extend into the upper receiver in order for the tube to bottom-out against the inside of the gas-key on the bolt carrier? It is difficult to photograph that relationship. But, that did not stop me from trying. Here, you see the PALMETTO upper receiver equipped with the Fulton Armory 15.5” gas tube.  Lying loose atop the upper receiver is the gas tube with the blue tape. After studying the relative positions of the parts, I represent that this photograph reasonably depicts – just from a visual standpoint – how far a gas tube would need to extend into the upper receiver in order to bottom-out against the inside of the gas key.



I want to point out that the photo shows that even the 15.5” gas tube stops well-short of any point where the mouth of the tube might come into contact with the gas-key on the bolt carrier.

As a small detail, I want to add that you can see where the mouth of the gas key stops inside the upper receiver if you look closely at the last photo in the post above.

Look at the bottom face of the magazine well. Along the bottom edge of that face, if you look closely, you will see a small silver mark on the receiver. Thats silver-sharpie ink that I applied to signify the most-forward point of travel of the gas key. That silver mark also coincides with the location of the blue tape on the gas tube I have mocked-up in the pic.

Question: How far does the short Palmetto gas tube actually engage the gas-key on the Palmetto bolt carrier?

See pics for answer.

My PA10 is over-gassed just like my another 308AR, I was actually thinking if a shorter gas tube would help reducing gas. Just want a little bit less. My PA10 does not have ejection issue, never check extractor tension! Extractor tension could cause ejection issue if does not hold the brass tight until ejector kicks it out. Typical check is remove the BCG, hold in hand, put a spent brass, held by extractor, shake a bit to see if the extractor would hold a brass in place. Never bother to check my PA10!

@W.E.G

Can't respond completely right now.  I'll get accused of being addicted to the computer.  You're spot on with your observations of the brass.  I was looking for swipe, which there is none.  Good claw marks versus the weak PSA extractor springs.

Also you can get tolerance stack/miss matched parts stack.  Long tube, long/forward gas key, less gas exhaust volume... all in the wrong place together, while it may work fine it may be taxing the limits of some components, like the lower receiver.  I would recommend getting by with as little gas as possible to get it to function.  ...reliably.   All the extra pressure/energy is just going to waste beating parts up.

@bfoosh06

Thanks for your reply and experience here.  Just waiting for the barrels to get back from being dimpled and I slap some uppers on them.

@W_E_G
hey, thanks for taking the time and effort to make these detailed measurement.  the subject of AR-10 Armalite gas tubes comes up often enough.  Thanks for putting this one to bed.  appreciated!

Serious question, do you find 3MOA to be acceptable with match ammo?

If it were me I would bench it, see what it will do, and if it wasn't 1.5MOA or less it would get a new barrel...

There are tons of $200 barrels out there that will do 1.5 or better.

Get into the $300+ and they tend to be MOA or better.

A 3/32” drill bit fits snugly in my gas port.

Don’t latch onto the 3 MOA thing on the basis of one group. I rarely shoot from a bench. I prefer to shoot prone with a sling. If I string elevation, that’s just the way it is. If the gun or ammo won’t deliver a high master score from a sling, I won’t spend much time with it. I intend to shoot it more to decide whether it meets my accuracy standards.

I have no opinion at this point on whether the gun is “over-gassed.” I have an adjustable gas block I can install if I feel like there is a recoil issue.

I have a few experiments to do yet.

couple of things, my disdain for PSA is well known.  That said, you buy from a company with a terrible record of QA and sending out products that are 'suspect' and one should NOT be surprised when things do click like they should.

that said, the pa-10s have gotten some great accuracy reviews on this board which is surprising and awesome given the price point.

really not sure why anyone would buy a pa-10 when you could simply build and aero for less if patient on the EE or for a little more.  blows my mind really

Another range-trip with the PA-10 today in its 15.2# configuration.

I still need to add some rail-covers, because the cheese-grater wasn't getting along so well with my left hand, even with a Creedmoor shooting glove.

I shot two targets. First target I made some corrections on the sight-adjustment. Target posted here, I left the knobs alone.

I have a bad habit of sending the first shot high. Hoping more familiarization, and rail-covers will mitigate that.

I fired all shots by feed from the magazine. But, I did break position on each shot to scope the shot in the spotting scope.

So far, I'm encouraged by the accuracy this barrel tries to provide when I do my part.

In the 15.2# configuration, recoil was quite civilized today. Ejection was postitive and consistent.

Thanks.

I want to shoot a match or two with it before I do any more surgery on it.

I fired another 80 rounds today. All good. Definition of “good” being no failures or other surprises. Well, except the pic-rails falling off the MLOK holes. I will make sure those all get Loctited.

Hoping for decent weather for Sunday’s match.

Shot three strings of 20 at 600 yards today at Fort Hill (Cumberland Maryland)
Wind was WHIPPING. Today was the most wind I have ever seen at Fort Hill. Wind was blowing shooting mats off the firing line and blowing-over shooting stools and chairs.
Temperatures in mid-40's all day.

First string was with my AR15 and my best 600-yard ammo (24.4 Varget and 80 SMK). Score was OK. At least it was a master score.
Second string was same AR15 but with my "short line" ammo (24.2 Varget and 75 Hornady). Huge difference in how much bullet was pushed around by wind.
Third string is what I promised to report. Shot with Palmetto PA-10 that has been subject of this thread. I think the gun did OK. My performance behind the gun... not so much.

Play-time with the PA-10 at 600 yard line.

My scorekeeper was kind enough to plot shot-location on each shot. The dot in each score-block indicates the approximate location of the impact relative to the center of the target. For instance, Shot #1 was a shot-value of 8, with impact at roughly 4 o'clock (per the dot).

First sighter at 600 way low off my estimate.
Second sighter at 600 came up 3 minutes (not enough)

First record-shot came up 2 more minutes (out the top)

second record-shot still too high and wind is making me its bitch already because I'm thinking about elevation issues, and not paying attention to what the wind was doing. Paid for that carelessness.

Shots 3-5 Paying attention to the wind and doing OK

Shot 6 probably a bad shot (corner shot), but why not correct off a bad shot?
Because shot 7. That's why. Out the right now.

Shot 8 Figured shot 7 was a bad shot, so don't correct windage.Send another shot to the same spot in the damn 7-ring.

Shots 9-12 creeping back from the right side slowly while the wind was playing me more.

Shot 13 Completely lose my mind. Bold correction. If you're gonna do bold corrections, might as well put a cherry on it by turning the knob the wrong direction. Hello 5-ring!

Shot 14 Still don't want to believe I screwed-up shot 13 so bad. Insufficient correction.

Shot 15 Getting really confused, and afraid to touch the knobs. So send another one into almost the same place in the 8-ring as previous shot.

Shots 16-17 Creeping back from the right again (favoring some instead of touching knobs).

Shot 18 Favored way too much. Way out the left.

Shot 19 Nothing to lose now. Just hold center, and try not to flinch. Finally in the X-ring.

Shot 20 Do it again. A 10.

Well, that was ugly. Mostly ME being ugly. If I had made better wind calls, and if I hadn't made a big brainfart on shot 13, overall score would have been quite a bit better.