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Palmetto PA-10 failure to eject


W.E.G.

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10 hours ago, 98Z5V said:

I went way deep into "proper gas timing" in here last night, and it's gone.  Also posted pics of my .260 Rem BCG, Aero/Toolcraft, and dual o-rings.  Gone today.

I had  improper “gas timing” on the flight from Winnipeg to Toronto yesterday. In the minature bathroom of a 737, it wasn’t pretty.

Edited by Sisco
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20 hours ago, 98Z5V said:

Also posted pics of my .260 Rem BCG, Aero/Toolcraft, and dual o-rings.  Gone today.

Here is a breakdown of my Ceratac ejector setup. Looks like the PSA when going together in the bolt; the clip doesn't stick up very far, and assembles easily with finger pressure. Posted it yesterday but; gone again. Let me know if anything is unclear or you want further measurements. The only thing I'm not incredibly confident on is the o-ring; tough to tell when I'm compressing it by a thousandth or two. 

IMG_41022.jpg

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Here's my Aero/Toolcraft extractor, with the duals:

P1080001.thumb.JPG.70c9e50f6be99dbbdda2ce60cfc5c445.JPG

P1080005.thumb.JPG.cfa91cb7d5b2f1a189ee0f5fa8a53ed3.JPG

P1080006.thumb.JPG.6a80eba7d0bbf8dcf7472a1e229946ce.JPG

 

It sucked to drive the extractor pin out.  It REALLY sucked putting the extractor pin back in.  I've never had an extraction issue on this gun. :thumbup:

Edited by 98Z5V
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So after following this thread and reading all the potential issues I might find with my PA-10 I took it apart yesterday for a quick inspection. 

I expected to find the feed ramps rough cut with a chainsaw, short gas tube and minimal apply pressure on the extractor.

The feed ramps aren't too bad, not rough at all and parkerized or nitride after the work was done because they are coal black.  The center lug is ground to a "knife" edge and probably why I'm seeing a visible scratch on my unfired bullets when I remove them.  I did this quite a bit in Colorado as I unloaded the gun at least a dozen times for the trip to and from the drop off points where I hiked in.

I didn't drive the roll pin out o the extractor and remove it because the gun runs flawlessly and I didn't want to strip it down that far.  I did check apply pressure and there is enough that it is extremely difficult to move it and has noticeable compression when you use a small screwdriver to pry it away from center.  This got me thinking some so I went to the PA website and checked my order:

PSA Gen 2 PA10 14.7" Mid-Length 7.62X51 NATO 1/10 Nitride 11" Slanted M-Lok Upper w/o BCG/CH, Pin & Weld ‒ 516445247

Hum, no BCG/CH.  So I must have purchased it separately and not from them.  This probably explains why my PA-10 has never had any issues.  The BCG is not theirs and before firing the first round out of it I converted it to the A2 stock with DPMS parts:

> DPMS LR-308 Buffer Rifle   308-BS-11          1  22.00
> DPMS LR-308 Buffer Spring  308-BS-10B         1   8.00

Not really knowing a lot about these 308 platforms (at that time) it appears that the success of my conglomeration of parts was much like a blind squirrel finding a nut.  I've ran at least 500 rounds out of it with ZERO issues.  This includes at least 4 different factory type 150-165 grain hunting loads (whatever was on sale at Walmart), some older loose Military rounds (pretty sure some of that was M-60 stuff), some Lake City Match, and plain old WCC 7.62 Military grade ammo, plus at least 3 different hand loads clear up to what I settled on (175 grain Barnes over Varget).

My gas tube is pretty short, very much like the pics on this thread.  I compared it to my DPMS and that gas tube sticks thru a LOT further.  I think we can pretty much rule out the short gas tube deal, but probably not a bad idea to have a little further engagement in that area as distance would equal time as far as applying rearward movement to the heavy bolt.

Anyhow, at least I'm not going to take my bolt apart and start looking for better parts for the extractor.  At this point I'm not sure where it was purchased, or who made it, but I'll look a little deeper in my emails and see if I can find out where it came from?........Cliff

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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.

 

2019-03-25%20-%20PA-10%20target_zpsojert

 

 

 

 

 

Edited by W.E.G.
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My PA-10 only has a 14.7" barrel and shows good potential for accuracy.  It doesn't like PMC ball ammo but did fine with everything else I've ran thru it.  To date the best groups were with some 150 grain Fushion factory loads and my 175 grain Barnes hand loads.  Both will go under an 1" at 100 yards.  Now if I could only get it to shoot like my 450 Bushmaster........Cliff

005.JPG

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Thanks.

I just installed the clicky-locky Magpul "XTM" cheese-grater covers on the back half of the graters.

Wow. That REALLY makes the rifle more comfortable to handle when wearing an NRA/CMP-legal shooting glove on my left hand. Instead of all the pressure being one rail of the grater on one finger-joint in the palme of my hand, the load is distributed WIDELY. I was going to take a day off from the range tomorrow. But, I'm so excited about the way that handguard feels now, I gotta go get some tomorrow!

Cosmetically, with the pic-rails, and the rail covers, the gun is looking a little porky in the handguard area now. But hey, the proof has to be on the scorecard. We shall see.

I want to go to Cumberland on Sunday for the 3x600 match but the forecast at Warrior Mountain range is looking mighty cold and wet at this point.

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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.
 

Palmetto%20PA-10%20-%20Fort%20Hill%20-%2

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7 hours ago, W.E.G. said:

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.

 


 

 

Despite wind, temp, & scores, sounds fun!

 

Happy the 308 is running, keep us updated on the dial in 

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On 3/24/2019 at 5:08 AM, Cliff R said:

My gas tube is pretty short, very much like the pics on this thread.  I compared it to my DPMS and that gas tube sticks thru a LOT further.  I think we can pretty much rule out the short gas tube deal, but probably not a bad idea to have a little further engagement in that area as distance would equal time as far as applying rearward movement to the heavy bolt.

I wish you could have read my post on gas tube length, gas port postitioning, and everything else I dumped about - that was here 2 days before you posted. It explained it all.  That explained exactly why everyone blows off the "short gas tube deal" but why it matters.  "M'eh, it's nothing..."

It IS something, if you understand this platform. 

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I get it, just wasn't in the "recipe" WAY back when I built my Alexandria Arms 308 and the PA-10. 

I just ran around gathering up parts, and very quickly found out (by trial and error) that although a good many parts are interchangeable between different platforms, there are parts that are specific to each rifle depending on whether it's Armalite, PA, Alexandria Arms, DPMS, etc.

I've got a decent size box of leftovers as a result of my learning curve.

Far as length of the gas tube, for sure longer engagement into the bolt carrier is going to provide additional time for the gas pressure to apply rearward force to the BC group.  I'm sure that the size of the hole in the gas block becomes a player in that deal as well.

Considering the operating pressure(s), powder burn rates, bullet weight, time the bullet spends in the barrel, etc, it's remarkable to me that the 4 rifles I've built all run flawlessly no matter what loads we've ran thru them.

I took a gander at the DPMS and noticed the gas tube extends thru a bit further than the PA-10, but didn't take any exact measurements.  For now I'm going to leave them alone unless we start running into function issues........Cliff

 

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As far as the PA-10 and accuracy, there is a local "guru" here who absolutely HATES PSA barrels, says there aren't worth two squirts of duck poop and pretty much anything else is an upgrade in the accuracy department.  The guy builds long range rifles and pretty knowledgeable but I've never spoke to him directly about any of it.

I have two PSA AR-15's with 16" barrels (they are the more expensive CHF in 1-7 twist, not the current "nitride" stuff they are pushing), and set-up for hunting ground hogs around these parts.  They are a little finicky about ammo, but shoot acceptably with PMC X-Tac and a couple of WWC Military loads I found stashed away in the ammo safe.  They aren't too fond of any M-855 loads and hate the currently available American Eagle and other Military knock-off stuff.

With PMC X-Tac I've fired several 300 yard groups laying over a big round hay bail (I like to simulate actual hunting conditions) that all go under 5" or so.  I haven't missed any groundhogs to that distance on calm days, so good enough for what I'm doing with them.

As far as using my PA-10 for 1000 yard matches, it doesn't show anywhere near the consistency and accuracy of the M-14 I was issued back in the 1980's for High Power matches.  That rifle was custom built by Navy Armorer's, with the full function removed, and it was nothing less than amazing for accuracy.  I've shot 18-10/4X with it at 1000 yards with a peep sight for crying out loud.  My eyes are so bad these days I doubt if I could match that deal at 500 yards with a 24 power scoped rifle!.......LOL.......Cliff

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Wind gets you both ways, so I never get too upset about my scores when it's whipping me and the bullets around some.

Hot/humid days will get you do, sweat dripping in your eyes, glasses fogging up, difficulty seeing the target at times. 

It's bad enough trying to take shooter error out of the equation, and adding in environmental stuff just makes things more difficult.

When I shot competition the real deal breaker was standing/offhand shooting.  Most shooters do reasonably well with a good rest, standing to kneeling, prone, etc.  When you stand up and nothing to lean against or other support......that deal very quickly separates the men from the boys!........FWIW.......Cliff

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43 minutes ago, Cliff R said:

Wind gets you both ways, so I never get too upset about my scores when it's whipping me and the bullets around some.

Hot/humid days will get you do, sweat dripping in your eyes, glasses fogging up, difficulty seeing the target at times. 

It's bad enough trying to take shooter error out of the equation, and adding in environmental stuff just makes things more difficult.

When I shot competition the real deal breaker was standing/offhand shooting.  Most shooters do reasonably well with a good rest, standing to kneeling, prone, etc.  When you stand up and nothing to lean against or other support......that deal very quickly separates the men from the boys!........FWIW.......Cliff

that be the truth right there.

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I shot a simulated 800-point match today with the PA-10.

All firing done at 200 yards (used reduced targets for rapid-fire prone and slow-fire prone).

 

I fired on the targets in the reverse-order of how they are typically fired in an NRA/CMP match (i.e. shot prone first). I had no reliable zero for sitting position or offhand position, so figured it made sense work-into a zero that would put me into the ballpark.

 

I’m pretty happy with the result.

 

You can see that I’m still having significant issues with maintaining a good elevation hold. I have this problem (holding consistent elevation) some when shooting the 5.56 AR. Clearly, I’ve got my work cut out for me to get a handle on it with the 7.62. To give you an idea where I am in terms of ability to hold, I reliably shoot “master” scores (94%+) from prone and sitting position. Typically expert scores (89% - 93%) offhand.

 

A few remarks about the targets:

 

600-yard target reduced for 200 yards.

Single-feed loading. Breaking position to reload on each shot.

When I began, I thought I already had a solid zero for the load (168 SMK / 41.5 gr. IMR-4895). First shot was that scratch-ten at ten o’clock. Figured good-to-go. Next several shots were SUBSTANTIALLY LOW. Several 7’s. That was pretty annoying, so I started cranking elevation onto the scope until I found my way back into the middle. Little-by-little, I ended up adding a total of TWO MINUTES UP elevation. At about the fifteenth shot, I was out the top. So cranked about a minute down. I think my elevation issue is a function of trigger-control and follow-through combined. I just need to keep working on it with this gun, or I’m going to continue to have slow-prone targets that look like this.

1-%20four%20targets_Page_4_zpsnrirkfbc.j

 

300-yard reduced for 200 yards.

Using same load as previous target.

You will notice this target also has vertical stringing. Perhaps slightly less-pronounced than the “600-yard” target. This target was fired with the same sight-settings as were used to fire the final shot on the “600-yard” target. Most shots are a bit right too. The displacement to the right is a function of getting on the trigger harder to maintain “rapid-fire” pace. Causes the shots to be pulled a little right for right-handed shooter.

1-%20four%20targets_Page_3_zpst3wweqqf.j

 

 

200-yard sitting rapid-fire target.

Using surplus Spanish “Santa Barbara” ammo.

I fired five sighters on a target not pictured in this post.

Using the same sight-setting as the previous target, and much to my surprise, the five sighters landed neatly in the 10-ring and at the ten o’clock position where I like my sighters to go for rapid-fire sitting-position. My sitting-position sighters always mislead and lie to me. The first string of ten shots was enough high and right, that I felt a sight adjustment was warranted. Not wanting to really screw the pooch, I made a too-conservative adjustment of only one click (one-third minute) down, and one click left. From the looks of the target, I could have used a more significant down and left adjustment. Still a master score for the first time firing this rifle from sitting position. So, I guess I’m not too disappointed.

1-%20four%20targets_Page_2_zpsuuxo8hrs.j

 

 

Offhand target.

20 shots standing.

Zero was a little weird on this one. Started with the same sight-setting as used on previous target. Over the course of the 20 shots, I ended up coming DOWN TWO MINUTES, and also RIGHT TWO MINUTES. So, blew a lot of 8’s high early. Those 7’s on the left, I’ll just own them. Would have probably been 8’s if I’d had the best dope on the gun, but still out there because I shot them out there.

1-%20four%20targets_Page_1_zpsvdl7quvi.j

 

 

Well, there it is. That’s what this rifle “could do” in a match. Really more like what I can do with this rifle in a match. As I mentioned before, I’m no great offhand shooter. I’m pretty dangerous once I get off my feet. I am confident that most of the points lost from supported positions were a function of not having a really good zero for those positions, and also imperfect shot execution. I don’t think this upper is a “lights out” specimen. But, its really not bad. The shooter needs the most work by far.

Edited by W.E.G.
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3 hours ago, W.E.G. said:

You can see that I’m still having significant issues with maintaining a good elevation hold. I have this problem (holding consistent elevation) some when shooting the 5.56 AR. Clearly, I’ve got my work cut out for me to get a handle on it with the 7.62. To give you an idea where I am in terms of ability to hold, I reliably shoot “master” scores (94%+) from prone and sitting position. Typically expert scores (89% - 93%) offhand. I think my elevation issue is a function of trigger-control and follow-through combined.

You will notice this target also has vertical stringing.

How is your breathing?  More often than not, vertical stringing and elevation issues are breathing-related. It's real easy to "bypass" or overcome breathing issues in the prone or on a bench, but it's different sitting or standing - way different. 

Using the same sight-setting as the previous target, and much to my surprise, the five sighters landed neatly in the 10-ring and at the ten o’clock position where I like my sighters to go for rapid-fire sitting-position. My sitting-position sighters always mislead and lie to me. The first string of ten shots was enough high and right, that I felt a sight adjustment was warranted. Not wanting to really screw the pooch, I made a too-conservative adjustment of only one click (one-third minute) down, and one click left. From the looks of the target, I could have used a more significant down and left adjustment. Still a master score for the first time firing this rifle from sitting position. So, I guess I’m not too disappointed.

As I mentioned before, I’m no great offhand shooter. I’m pretty dangerous once I get off my feet. I am confident that most of the points lost from supported positions were a function of not having a really good zero for those positions, and also imperfect shot execution. I don’t think this upper is a “lights out” specimen. But, its really not bad. The shooter needs the most work by far.

Zero isn't going to change.  Applying a solid shooting platform is, though, the higher you get off the ground.  Once you zero, it is what it is.  Gotta use bone structure as much as possibly, rely as little as possible on muscle support, in all positions - but it's tougher to do sitting, and even tougher standing. Breathing (control of breathing when breaking the shot) gets more important, the higher you get off the ground (prone, the sitting, then kneeling, then standing).  Just what I'm seeing and asking, based on what I'm interpreting from your info...   :thumbup:

 

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