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  #1  
Old 11-27-2021, 07:16 AM
Hummer Hummer is offline
 
Join Date: Oct 2013
Location: Aiken, South Carolina
Posts: 92
Default Bolt on PA10 won't open with empty chamber

Got a PSA PA10 a couple years ago and from the get go I noticed the bolt wants to remain in battery even with empty chamber.

It feeds, fires, extracts, ejects with Fed Match just fine. After shooting it is cleaned both the bore and the bolt carrier is removed and cleaned.

If left say over night it will be a little hard to open but if left for a week it is really hard to open even with upper not engaging lower.

Anybody ever had this happen?

I am thinking the cam pin is oversize or the internal cam way dimensions in the bolt carrier are out of spec.

Update: Just got email from guy I got the rifle from. He bought the upper and lower assemblies from PSA and put them together. With the bolt in the "in battery"position the cam pin jams tight in the back of the bolt carrier opening. I think it needs relieving but no way to do it with the bolt carrier assembled.

2nd UPDATE:

This morning I put a new unfired never loaded 308 case in the chamber, dropped the bolt home and it locked up just like it was empty.I just fired a new Winchester case with a handload and measured the fired case with a MO Gage and** the** headspace is .004 over GO which is .002" short of NO GO which is in spec.** **FIred case base dimension on fired case is** ,472" which is max.I looked at locking lugs with bore scope and** saw nothing that would cause a lockup like I am getting.I am at a loss to figure out what is happening unless something is wrong with the way the locking lugs on the barrel extension/or bolt are not milled correctly?????

As it stands to have it ready to go I would have to leave it loaded with round in chamber and hammer cocked which obviously is not a good idea.
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Distinguished Smallbore Prone & Highpower Rifle # 514, Presidents 100, Member US Palma Teams & US Dewar Teams. Palma Twenty, Certified Small Arms and Ammunition Test Director Aberdeen Proving Ground, Maryland. Conducted small arms testing for US Army TECOM, Army Materials Systems Analysis Activity and the US Marine Corps.
Commandant USMC Commendation for "Exceptional Performance" on M16A1E1 Rifle Testing (adopted as M16A2) Army Commendation Dover Devil Cal 50 Machinegun Program.

Last edited by Hummer; 11-28-2021 at 01:13 PM.
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  #2  
Old 12-01-2021, 08:47 PM
ontheroad ontheroad is offline
 
Join Date: Oct 2009
Posts: 30
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Lifetime warranty on PSA guns, even if you aren't the original owner. Run it out to Columbia and they should make it right. Or send in the form and they should provide a prepaid return label: https://palmettostatearmory.com/medi...equestForm.pdf
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  #3  
Old 12-02-2021, 07:47 AM
Hummer Hummer is offline
 
Join Date: Oct 2013
Location: Aiken, South Carolina
Posts: 92
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I contacted them and took it over first of week and they made it like new.
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Distinguished Smallbore Prone & Highpower Rifle # 514, Presidents 100, Member US Palma Teams & US Dewar Teams. Palma Twenty, Certified Small Arms and Ammunition Test Director Aberdeen Proving Ground, Maryland. Conducted small arms testing for US Army TECOM, Army Materials Systems Analysis Activity and the US Marine Corps.
Commandant USMC Commendation for "Exceptional Performance" on M16A1E1 Rifle Testing (adopted as M16A2) Army Commendation Dover Devil Cal 50 Machinegun Program.
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  #4  
Old 12-02-2021, 08:06 AM
ceresco ceresco is offline
 
Join Date: Oct 2009
Posts: 8,220
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The AR type rifles have a lot of moving parts in the bolt/bolt carrier mechanism and lack the leverage and authority of bolt rifles. I have noticed the tendency to open with considerable (sometimes extreme) difficulty, especially when stored for a time. IIRC, my PA 10 has exhibited this at times. I suspect that the stickiness is some combination of lubricants, lack of lubricants, fouling and new metal surface finish, etc. Since the rifles does function--more or less correctly, I suggest trying different lube products and possibly lapping the cam pin or other wear points. It may be that simply more rounds or a session of "dry" operation would be helpful. If you send it back to PSA, I suspect someone will spray it with WD40, cycle it a few times and send it back..... Good Shooting. ... Addendum: just saw your post. Did they tell you what they did??

Last edited by ceresco; 12-02-2021 at 08:08 AM.
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  #5  
Old 12-02-2021, 08:27 AM
Hummer Hummer is offline
 
Join Date: Oct 2013
Location: Aiken, South Carolina
Posts: 92
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Be assured it was lubed correctly and everything was still wet in it from the last time I shot it several years ago. I was right there when it was checked out and when they got through it was like new.

I was really impressed with their the Palmetto Armory staff and could not have asked for better treatment.

Sounds like you have exactly what I did. I suggest you contact them. I think you will be impressed.

I have four ARs in 5.56 (One RRA, two parts build ups, one Colt HBAR w/ Delta barrel) and have had them for years. THe PA 10 I got on a trade and it was no problem until I had run maybe 200 rounds through it. I know the previous owner and it did not give him any problem and all I ran in it was Fed Match 168s that was loaded with 4895.

Went out and ran 22 rounds on it this afternoon with not the best ammo and it ran like a champ. I put 15 rounds in a 30 rd PMAG, and weighed it with bipod and it is exactly 13 lbs. Might just start carrying it on my 5 mile walks in the AM for the exercise. Now I am carrying a Rem 7600.

The ammo I ran today is IMI loaded 35+ years ago with Sierra 150 gr. spitzer hunting bullets. Had a 6 o'clock wind at about 20 MPH and the vertical dispersion was about 9" at 300 yards but the horizontal was X ring width. Will run some Fed Match maybe next week.
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Distinguished Smallbore Prone & Highpower Rifle # 514, Presidents 100, Member US Palma Teams & US Dewar Teams. Palma Twenty, Certified Small Arms and Ammunition Test Director Aberdeen Proving Ground, Maryland. Conducted small arms testing for US Army TECOM, Army Materials Systems Analysis Activity and the US Marine Corps.
Commandant USMC Commendation for "Exceptional Performance" on M16A1E1 Rifle Testing (adopted as M16A2) Army Commendation Dover Devil Cal 50 Machinegun Program.

Last edited by Hummer; 12-02-2021 at 05:34 PM.
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  #6  
Old 12-15-2021, 06:07 AM
lapriester lapriester is offline
 
Join Date: Oct 2009
Location: Cobb, N California
Posts: 16,739
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You may want to check the clearance of the forward assist and the bolt serrations. On the last two PA10 uppers I assembled with all PA10 parts from PSA, I had to re taper the ends of the forward assists to enable opening the bolt from closed. I had to remove the two forward assists to get the bolts open from closed. PA10's function fine once you get all the unnecessary bugs and ill fitting part problems resolved that shouldn't be there on a quality product to begin with. I have uppers in 308, 260 Remington, 6.5 Creed and 243 Winchester. Killed a Cow Elk in New Mexico 3 years ago with the 308 dead in her tracks.

Last edited by lapriester; 12-15-2021 at 06:10 AM.
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  #7  
Old 12-15-2021, 07:20 AM
Hummer Hummer is offline
 
Join Date: Oct 2013
Location: Aiken, South Carolina
Posts: 92
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yep that describes what I saw on my bolt. They replaced the bolt and carrier and I am good to go now.

I am getting vertical stringing at 300 yards with little windage which I think is coming from a Burris Scope I have on it. I am going to change the scope and see if it is still doing it.
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Distinguished Smallbore Prone & Highpower Rifle # 514, Presidents 100, Member US Palma Teams & US Dewar Teams. Palma Twenty, Certified Small Arms and Ammunition Test Director Aberdeen Proving Ground, Maryland. Conducted small arms testing for US Army TECOM, Army Materials Systems Analysis Activity and the US Marine Corps.
Commandant USMC Commendation for "Exceptional Performance" on M16A1E1 Rifle Testing (adopted as M16A2) Army Commendation Dover Devil Cal 50 Machinegun Program.
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