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Discussion Starter #1
Hello, new here and this is my first HK style rifle of any sort so this has been a learning process. I just bought a PTR-91 A3R and in the first 50 rounds through the gun I have 7-8 failures to eject/extract. When it does eject it doesn't seem to eject with the kind of force described by most 91 owners (cases barely dented at all or not at all only going 5-10 feet max). The ammo I was using is new commercial 7.62 nato spec and certainly did not seem to have defects. My bolt gap is 0.18 and stable, I have cleaned and lubed it half to death with no change. When failure to eject occurs the bolt carrier is left partially back (where it would rest if you slowly lowered it). In some cases the bolt required putting on gloves and yanking the hell out of the handle to pull the case out of the chamber.

I have the 12 flute "GI" barrel which to my understanding is supposed to be more forgiving of ammo choices. The main thing I'm noticing is my brass has fairly defined marks from the fluting on the case necks. When looking at other brass at the range fired from this type of rifle the fluting marks were purely visual and didn't seem to actually deform the brass but with mine the neck of the case is practically molded to the flutes with defined ridges.





If anyone knows what the problem is I would appreciate the help. I think I am going to call PTR tomorrow and make a warranty claim if its not something simple. I want this to work right.
 

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My GI works just fine and there are definitely impressions in the brass. I don't think that is where your problem lies. You have taken a rag wet with solvent thru the mag opening and cleaned the trunion depressions right?
 

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Sounds like it could be an extractor or extractor spring issue. The springs are only like $8 so it's an easy thing to replace and test.
 

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If you can move the extractor with your finger then the extractor spring is toast and needs replacing. Have you had any double feeds, as that is the most common way the spring gets ruined.

The marking of the brass by the flutes is dependent on the quality of the brass and not your rifle. When I shoot ZQI the soft brass fireforms to the flutes, while harder mil-surp brass comes out with just some powder marks.

Did you break the rifle down and do a thorough cleaning prior to shooting it? Did you lube it after the cleaning?

If you bought this rifle new then contact PTR about the issue.
 

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Discussion Starter #5
If you can move the extractor with your finger then the extractor spring is toast and needs replacing. Have you had any double feeds, as that is the most common way the spring gets ruined.

The marking of the brass by the flutes is dependent on the quality of the brass and not your rifle. When I shoot ZQI the soft brass fireforms to the flutes, while harder mil-surp brass comes out with just some powder marks.

Did you break the rifle down and do a thorough cleaning prior to shooting it? Did you lube it after the cleaning?

If you bought this rifle new then contact PTR about the issue.

I will admit this ammo woild not be what I call nice, but it was new factory NATO spec ammo and my understanding is that .308 uses thinner brass. I have not had any double feeds and the brass that fails to eject is VERY stuck in the chamber. I couldn't swear this is a failure to extract because it is possible that the brass is being shoved back into the chamber after not ejecting but the lack of double feeding and the lack of damage to the brass make me think the bolt never opened at all. I have taken down and cleaned the rifle at least 3 times during this 50 rounds. I have greased the friction points on the carrier and oiled nearly everything else. I cleaned the chamber and the locking points. The bolt and rollers are moving very smoothly and the extractor spring is so tight I can't move it. (Is it possible it's too tight?) The ejector it's self was a little rough but not much and is definitely not bent.

I plan on testing this with steel case and higher end brass soon but I will certainly be disappointed if this gun cannot run all new commercial 7.62x51 as my understanding is the 12 flute models should be able to.
 

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In the OP when you said "My bolt gap is 0.18 and stable", did you mean 0.18mm or 0.018"? If it's .18mm then it's a little out of ideal spec and it might help to go up a size of rollers.

e: I would try different ammo first though. It does sound like a weird issue with the cartridges getting more stuck than they should.
 

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I will admit this ammo woild not be what I call nice, but it was new factory NATO spec ammo and my understanding is that .308 uses thinner brass. I have not had any double feeds and the brass that fails to eject is VERY stuck in the chamber. I couldn't swear this is a failure to extract because it is possible that the brass is being shoved back into the chamber after not ejecting but the lack of double feeding and the lack of damage to the brass make me think the bolt never opened at all. I have taken down and cleaned the rifle at least 3 times during this 50 rounds. I have greased the friction points on the carrier and oiled nearly everything else. I cleaned the chamber and the locking points. The bolt and rollers are moving very smoothly and the extractor spring is so tight I can't move it. (Is it possible it's too tight?) The ejector it's self was a little rough but not much and is definitely not bent.

I plan on testing this with steel case and higher end brass soon but I will certainly be disappointed if this gun cannot run all new commercial 7.62x51 as my understanding is the 12 flute models should be able to.
NATO Spec has nothing to do with how hard/soft the brass is. What is the brand of ammo you are using as there might be some known issues with it?

Have you used more then one magazine during this time frame?

What do you mean by "the ejector was a little rough"? Pictures?

If you bought this rifle new then contact PTR about this issue and they WILL take care of you.
 

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Discussion Starter #8 (Edited)
In the OP when you said "My bolt gap is 0.18 and stable", did you mean 0.18mm or 0.018"? If it's .18mm then it's a little out of ideal spec and it might help to go up a size of rollers.

e: I would try different ammo first though. It does sound like a weird issue with the cartridges getting more stuck than they should.
sorry I meant 0.018. It was exactly the upper limit of an in spec bolt gap according to the manual. That was both before and after the 50 rounds.


NATO Spec has nothing to do with how hard/soft the brass is. What is the brand of ammo you are using as there might be some known issues with it?

Have you used more then one magazine during this time frame?

What do you mean by "the ejector was a little rough"? Pictures?

If you bought this rifle new then contact PTR about this issue and they WILL take care of you.
The ammo I used was what the FFL had. CBC (from brazil) 7.62x51 147gr. I wouldn't doubt its sub par. I did just buy a box of Remington, Federal, and Hornady brass .308 to test out.

I have only used one magazine though I have several now. its a 1965 production aluminum mag. I also have a few 1980s production ones and some steel. All of them in unissued condition.

By rough I mean the movement of it was not 100% smooth. Its movement was a little coarse but not really enough to make me think there is a problem.

EDIT: seems I jumped the gun. I just read a review of this ammo from a PTR 91 owner saying it jammed his gun every shot after 5 shots. If that's par for the course with this ammo I guess I was doing better than expected lol.
 

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sorry I meant 0.018. It was exactly the upper limit of an in spec bolt gap according to the manual. That was both before and after the 50 rounds.
The upper gap is .020 according to HK and PTR and the rifle will work fine at that limit. IIRC PTR does mention that between .015 - .018 is what they consider "ideal".

The ammo I used was what the FFL had. CBC (from brazil) 7.62x51 147gr. I wouldn't doubt its sub par. I did just buy a box of Remington, Federal, and Hornady brass .308 to test out.

I have only used one magazine though I have several now. its a 1965 production aluminum mag. I also have a few 1980s production ones and some steel. All of them in unissued condition.

By rough I mean the movement of it was not 100% smooth. Its movement was a little coarse but not really enough to make me think there is a problem.

EDIT: seems I jumped the gun. I just read a review of this ammo from a PTR 91 owner saying it jammed his gun every shot after 5 shots. If that's par for the course with this ammo I guess I was doing better than expected lol.
CBC was the ammo I first put through my PTR91 and I had zero issues with the couple hundred rounds of it I used.

When you say your extractor had "rough movement" how exactly were you moving it? It should move barely if at all with finger pressure. If you stuck a shell casing under it and moved it around while you had rifle disassembled you might have messed up the extractor spring.
 

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Discussion Starter #10
The upper gap is .020 according to HK and PTR and the rifle will work fine at that limit. IIRC PTR does mention that between .015 - .018 is what they consider "ideal".


CBC was the ammo I first put through my PTR91 and I had zero issues with the couple hundred rounds of it I used.

When you say your extractor had "rough movement" how exactly were you moving it? It should move barely if at all with finger pressure. If you stuck a shell casing under it and moved it around while you had rifle disassembled you might have messed up the extractor spring.
So I just ran a box of federal, a box of Remington, and a box of hornady brass through the gun with no cleaning between shots using the same mag as before and zero failures to extract. The only problem was the hornady ejected oddly. Two of the casings hit the side of my head on the way back. One landed in my lap. One stovepiped. Any idea why? But it does seem it was the CBC that was to blame. Also this brass has hardly any fluting marks. Nothing like before. Does your ptr have 12 flutes or fewer? That could explain how it runs fine in yours.

On a side note I did clean the hell out of the chamber this time so it is possible I removed some grease that was clogging it before. As long as it works with the three most common brass loads I'm not going to complain.
 

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Sorry I just realized you were talking "ejector" when you mentioned it was rough and I was thinking "extractor". The Ejector should move up and down freely and if it doesn't then that might explain your strange ejection.

I have the newest chamber which should be the same as yours.

You should check your extractor after any miss feed. You will want to keep several spare extractor springs on hand as the HK design allows the spring to be over extended and thus ruined during a miss feed.
 

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Discussion Starter #12
Sorry I just realized you were talking "ejector" when you mentioned it was rough and I was thinking "extractor". The Ejector should move up and down freely and if it doesn't then that might explain your strange ejection.

I have the newest chamber which should be the same as yours.

You should check your ejector after any miss feed. You will want to keep several spare extractor springs on hand as the HK design allows the spring to be over extended and thus ruined during a miss feed.
Okay, I'll make sure to pick up extras. I'll probably also polish the ejector where it rubs against the trigger housing although I'm probably getting the ambi trigger group anyway.
 

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I bought my PTR91 A3R about 7 months ago and had the same issues you speak of. I had picked up some Perfecta .308 ammo prior to heading to the range for the first time, and ended up with the same results as you. Would weakly eject the casings, and finally fail to eject all together. My buddy that came along with me brought his AR-10 and had some ZQI 7.62x51 NATO. After switching to the ZQI, my PTR ran flawlessly and was ejecting brass half-way across the range it would seem. I again tried a magazine of the Perfecta one last time, and it became a jam-o-matic again... Switched back to the ZQI, and no issues! Funny enough, the Perfecta ran with no issues in my buddy's AR-10. Needless to say, my buddy began to talk **** saying I should have just bought an AR-10 like him and I would not have to worry about ammo issues. ****.

I gave the remainder of the Perfecta ammo to him, and bought a few cases of ZQI the next day.
 

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I shot 40 rounds of CBC through my PTR91 today with no issues and good accuracy out to 500 yards. The CBC brass is almost as soft as the ZQI as it definitely fire formed into the flutes. The CBC appears to be loaded hotter then the Tula I shot last as my POI shifted significantly upwards.

Full disclosure, I bought the CBC right after Sandy Hook so it might not be the same as a more current batch.

Though I have actually had zero issues (other then varying POIs) with any brand of ammo that has gone through my PTR91. Ammo has included Wolf, Tula, CBC, Perfecta, surplus from various countries, Herters and US Mil issue Lake City.
 

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Discussion Starter #15
The manual does say you might experience jams the first 200-300 rounds. My hope is this gun will be more tolerant of cheap ammo after the break in period is up.
 

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This also sounds like the problem that I was having w/ my rifle while using CBC ammo. The lot number for my box of ammo is CBC 346/15. I only managed to fire two mags through mine and at the time I did not have any different ammo to try, but did use two different magazines. I just bought a battle pack of Hirtenberger 7.62 NATO ammo though and am hoping there will be no issues w/ it.
 
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