W.E.G.

The diameter of each extractor at the axis pin is identical. I haven't actually cross-installed them to confirm that one can go in the other bolt. Rifles are locked up now, so will have to get around to that test another time. I have a Fulton extractor and spring and extractor-buffer on order. Probably will see how that shakes out when the order arrives.

AR15 extractor is significantly smaller. I was going to post a pic, but they aren't even close in comparative size.

Thank you for that suggestion. I may give that a try as opportunity presents.

Not an optical illusion. The Palmetto claw is 0.020" narrower than the Fulton claw at the outer lip of the claw. Hard to measure the DEPTH of the claws, but my Mark I fingernail senses that the depth of each claw is pretty similar.

Well, remember I've got the Magpul Gen 1 UBR stock on the gun now. The UBR is staying. I'm not sure what margin there is in re-installing the spring from the A5-length Palmetto crapsalapsible $8 stock setup just to see if the A5-length spring will work in a Gen 1 UBR. As an aside, if you happen to install a Gen 2 UBR on your rifle, the Gen 2 UBR receiver extension is A5 length. So, you could (and you should) make sure you use an A5-length spring unless you use the spacer that comes with the Gen 2. The spacer allows you to use carbine-length components (buffer and spring) in the Gen 2 UBR. I have a Gen 2 UBR on a different AR-15. I'm going to keep the Gen 1 UBR on the Palmetto PA-10 for reasons that are unique to my circumstance.

Although, for another $50 over the price of the fancy-shmantzy JP extractor, I can get another complete Fulton bolt, and not be concerned about mix-matching parts in the Palmetto bolt - a bolt that might be snakebit in who-knows-what sort of way. Plus, I need to make another order to Fulton anyway to get another 15.5" gas tube to install on the original non-adjustable gas block from the Palmetto gun. CMP rules have been interpreted to dis-allow adjustable gas blocks on service rifles. I'd rather not molest the Seekins block with my Harbor Freight welder to render it non-adjustable. And I don't feel like swapping a single gas tube back-and-forth between different gas blocks every time I futz with the configuration. I'll just put a new (longer) gas tube on the Palmetto block, and keep myself in the clear on Service Rifle competition rules. The adjustable block with the new tube can hang around in the spare-parts-box in case I feel like playing with gas adjustments.

At this point, the gun works just fine with the Fulton bolt. I'm not sure how much study I'm going to do "in the name of science" to figure out why the Palmetto bolt continues to fail. I'm tempted to give the JP Enhanced extractor a try https://jprifles.com/buy.php?item=JPEB-308EX in the Palmetto bolt. Their comment in the instructions is encouraging if you take it at face value:

The two significant differences I can see between the Palmetto bolt and the Fulton bolt are: 1. The claw on the Palmetto bolt is narrower than the Fulton bolt. 2. The Palmetto bolt uses a pair of counter-wound springs. Whereas, the Fulton bolt uses a single spring with a central insert of some sort of orange polymer reinforcement. Both extractors measure 0.312" across at the location for the axis-pin. Palmetto extractor in top of pic. Fulton extractor in bottom pic.

Bad news. and Good news. The bad news is, the gas tube replacement did NOT solve the failure-to-eject issue. With the new gas tube, and loaded with a single round, the rifle would fire, and it would extract the spent case, just like before, leaving the spent case languishing on top of the magazine follower. I had the foresight to take a second AR-10 (actually a DPMS LR-308T - which is a "first generation" DPMS AR-10 type rifle) to the range also today. By happenstance, the DPMS gun was equipped with a Fulton Armory bolt https://www.fulton-armory.com/bolttitanstripped-2.aspx which I have been successfully testing in the DPMS gun. I removed the entire bolt/carrier assembly from the DPMS gun, and I installed that assembly in the Palmetto gun in place of the entire Palmetto bolt/carrier assembly. Immediately, the ejection problems were solved. With the DPMS-carrier/Fulton-Armory-bolt, the Palmetto gun ran just fine. One establishing that the Palmetto gun would run fine with the DPMS/Fulton assembly, I then installed JUST THE FULTON BOLT in the Palmetto Carrier assembly (including Palmetto cam pin and Palmetto Firing pin). The gun continued to run fine with the Fulton Bolt installed in the Palmetto carrier. The remainder of the day's firing was done in this configuration. The adjustable gas block was set such that the port adjustment was three revolutions out for all firing today. I did not try to "tune" the gas block whatsoever during today's outing. I fired about twenty shots with Santa Barbara milsurp ammo to verify function. Then I fired about thirty rounds of a handload that has served me well through the years. 41.5 grains IMR-4895 and a 168-grain Sierra MatchKing. The pic below shows a group I fired for accuracy at 200 yards. All firing was prone, and supported only by a military sling. I am encouraged by the accuracy delivered by the Palmetto barrel. The two high shots in the group were each shots that just felt a little awkward when I fired - as though I was anticipating recoil, and tensing my body. Also the gun is butt-heavy in its current configuration. The heavy butt may simply be the reason for the two high shots. A little weight forward tends to keep the muzzle down at the moment the trigger breaks. The rifle was equipped with a Geissely National Match trigger that weighs about 5 pounds. The buttstock was a Magpul UBR at full extension (no way I'm shooting nose-to-charging-handle) with this hard-kicker. The buttstock was equipped with the Stealth Ballistics butt-weight. Overall weight of the gun currently is about 12.5 pounds. I plan to add about another pound to the handguard to get it to balance a little more forward. Right now, with the weighted buttstock, the gun is butt-heavy.

70 degrees and sunny and no work range trip today I’ll take a Pmag and a metal mag and several types of ammo and the DPMS rifle in case I need to scavenge parts.

Note that the front end of the gas tube sits at some depth inside the gas block once the cross-pin has been secured. Here's our protrusion of the tail of the 15.5" gas tube into the upper receiver. Fulton Armory did a good job of pre-bending the tube. Excellent clearance at the barrel nut. Pic of the passage at the cloverleaf-hole. Clearance of the gas tube without interference with the charging handle. Bolt and carrier assembly in full battery without interference. Rear view of bolt and carrier assembly in full battery.

comparison of old tube and new tube When I tried to install the new tube, I had hopes that I might have on-hand a new roll-pin of suitable diameter. I have a supply of various-sized roll pins from Brownells. The 1/16" pins actually measured to 0.070", although the math says a 1/16" pin should be 0.62". Not that it mattered because the "1/16" pin was too small even at an actual size of 0.070". Next size up in my supply is 5/64. Which according to the math should be 0.0781" - or virtually the exact same size as the pin that came with the original Palmetto gas block. Similar to the 1/16" pins, the 5/64" pins were larger than the nominal size on the package. The actual diameter of the 5/64" pins is 0.081". I'll venture that is the size used with the original Palmetto gas block. Remembering the ordeal of beating the tarnation out of that 0.080" Palmetto pin to get it to zig-zag its way through the Seekins adjustable gas block, I considered other options. the problem is that the Seekins adjustable block is off-center just enough that the roll pin has to do a zig-zag turn to travel from one side where it is inserted to the other side where it will emerge. For motivation, I gave the old roll pin a try, and it fought me hard. I tried a new 1/16" pin, but fit was sloppy. Enter the FINISHING NAIL - which just happens to be 0.075". Perfect. The nail went through the gas block and the tube with only the slightest friction. Once in place, the gas tube was secure, and did not rotate at all. Cosmetically not ideal. But unless you remove the handguard, it will never be seen. If I ever have to remove the nail, I doubt it would be re-usable. No problem. I have a lifetime supply of finishing nails in the cabinet. Even got to bust out the WECSOG Dremel to clean up the rough cut from the nippers.

comparison of old tube and new tube When I tried to install the new tube, I had hopes that I might have on-hand a new roll-pin of suitable diameter. I have a supply of various-sized roll pins from Brownells. The 1/16" pins actually measured to 0.070", although the math says a 1/16" pin should be 0.62". Not that it mattered because the "1/16" pin was too small even at an actual size of 0.070". Next size up in my supply is 5/64. Which according to the math should be 0.0781" - or virtually the exact same size as the pin that came with the original Palmetto gas block. Similar to the 1/16" pins, the 5/64" pins were larger than the nominal size on the package. The actual diameter of the 5/64" pins is 0.081". I'll venture that is the size used with the original Palmetto gas block. Remembering the ordeal of beating the tarnation out of that 0.080" Palmetto pin to get it to zig-zag its way through the Seekins adjustable gas block, I considered other options. the problem is that the Seekins adjustable block is off-center just enough that the roll pin has to do a zig-zag turn to travel from one side where it is inserted to the other side where it will emerge. For motivation, I gave the old roll pin a try, and it fought me hard. I tried a new 1/16" pin, but fit was sloppy. Enter the FINISHING NAIL - which just happens to be 0.075". Perfect. The nail went through the gas block and the tube with only the slightest friction. Once in place, the gas tube was secure, and did not rotate at all. Cosmetically not ideal. But unless you remove the handguard, it will never be seen. If I ever have to remove the nail, I doubt it would be re-usable. No problem. I have a lifetime supply of finishing nails in the cabinet. Even got to bust out the WECSOG Dremel to clean up the rough cut from the nippers.

Fulton Armory 15.5" gas tube rececived. This looks promising

A 3/32" (0.09375") drill bit fits very snug. At most, the hole can't be more than a thousandth larger than the drill bit.

Shipping notice says Fulton gas tube to be delivered by end of day Wednesday. Weather for Thursday looks favorable for range trip.

Ordered early Monday morning. Got an immediate order confirmation in email. No shipping confirmation yet. But, not sure Fulton does shipping confirmations for parts-orders.

In my case, BIG SQUIRRELS, were the primary motivation.

Thank you all for your thoughtful replies. I am going to pursue the too-short-gas-tube possibility. I ordered a 15.5" tube from Fulton Armory today: https://www.fulton-armory.com/gastuberifle-1.aspx My gas tube indeed appears to be shorter than it ought to be by "rifle" standards. The silver mark on outside of the upper receiver corresponds to the end-point of the tube inside the receiver.

I am familiar with some threads on this site regarding substitution of a mid-length gas tube in 16" PA-10 guns and that substitution having a positive result. Take note that my gun is not a carbine (16") or a mid-length (18"). Mine is a TWENTY-INCH barrel. This product: https://palmettostatearmory.com/psa-gen2-pa10-20-rifle-length-308-win-1-10-stainless-steel-15-m-lok-upper-with-bcg-and-ch-5165447981.html Here's a pic of my gas tube protrusion.

I have headspace gages, and lots of experience measuring headspace. The PSA gun will swallow the 1.631 gage with the PSA bolt and carrier. That same combo will not swallow the 1.632 gage. If I put the DPMS carrier and bolt in the PSA gun, the PSA gun will swallow a 1.633 gage. That same combo will not swallow a 1.634 (.308 Win. NO-GO) gage. . . Now for further comparison, let's see how that swap works out on a Gen 1 DPMS LR-308T. The DPMS gun will swallow a 1.633 gage with the DPMS carrier and "porris" bolt. That same combo will not swallow a 1.634 (.308 Win. NO-GO) gage. When I put the PSA bolt and carrier in the DPMS gun, the DPMS gun will swallow the 1.632 gage just barely. Bolt seems to lock up on the 1.632, but requires the "pogo" maneuver to get the gage out of the chamber. That same combo will not swallow a 1.633 gage. Point of all this? I think we can say that the DPMS and PSA bolt/carrier assemblies interchange. My particular sets are only 0.001" to 0.002" different headspace if I swap them. On a minor note, I will also point out that the PSA carrier is cut with serrations to accomodate the forward-assist mechanism. The DPMS gun is a slick-sided gun, and has no forward-assist mechanism. Neither does the DPMS carrier have any serrations.

First post here. I'm Admin over at the FAL Files if anybody cares. Having trouble with a Palmetto PA-10. Wont' eject worth a darn. Rifle fires normally, but will not reliably expel the spent case. Configuration: Gen 2 PA-10 20" upper Gen 2 PA-10 lower with aftermarket buttstock and trigger Magpul UBR Gen 1 buttstock KAK 5.3 ounce carbine buffer DPMS LR-308 carbine buffer spring Geissele National Match trigger Seekins adjustable gas block Same malfunction in current configuration as was present before substituting a the KAK buffer for a 3.8 ounce DPMS carbine buffer and Palmetto's factory-furnished non-adjustable gas block. Today's range report: Fired about 50 rounds. Had about 30 malfunctions. Tried various settings on the adjustable gas block. With the adjustment screw turned about three turns out, the bolt would cycle far enough back to pick up the next round from the magazine. The PROBLEM is that no matter what gas-setting, the bolt would frequently fail to expel the spent case from the upper receiver. This of course caused the bolt to try to cram the spent case, and the round from the magazine, both into the chamber. Which does not work. I tried firing the rifle single-shot a number of times. About half the time, the rifle would fire normally, except the spent case would not eject from the upper. The spent case was just left lying on top of the magazine follower. The ejector appears to have ample spring tension, and it moves freely in the bolt. The extractor shows no obvious defects. The extractor spring is actually a two-spring jobby (one smaller spring counterwound inside a larger spring - just like the recoil springs in a FAL). A black rubber O-ring is also present to reinforce the extractor spring. All that said, the extractor is failing to extract the spent cases sufficiently that they can be ejected from the rifle. Inspection of the spent cases shows an extractor-mark on the rim of the cases, but no signs of bending, tearing, or any sort of worrisome deformation of the case rim. The walls of the case do not show any signs of impression into any deformations in the barrel-chamber. I probed the walls of the chamber gently with a dental pick, and I detected no roughness or irregularities such that the brass might be caused to "stick" in the chamber. Two types of ammo were used in the test. 40 rounds of Santa Barbara milsurp, and about 15 rounds of a handload (168 SMK and 41.1 grains TAC in a Lake City Match twice-fired-previously case). My reason for firing so many rounds, notwithstanding the persistent malfunction was to hope to "break in" whatever was causing the malfunction, and have it disappear. No such luck. My best guess is that the extractor is letting go of the spent case too soon, and thereby allowing the case to languish and interfere in the upper receiver during cycling. If I had known the extractor was going to develop as the likely culprit, I would have brought my entire DPMS LR-308 bolt/carrier assembly, and I would have substituted the DPMS assembly for the Palmetto assembly to see if the substitution would cause the rifle to cycle. I do know the DPMS assembly has NEVER failed in the DPMS rifle. As circumstances permit this week, I will try to make that experiment happen promptly Looking for advice.