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New member with some PTR-91 problems.

11766 Views 33 Replies 9 Participants Last post by  Whitex2000
Hi everyone. I'm new to the boards and decided to join so i could get a little help with some problems.

I have a PTR-91 with the serial number starting at AW8, so i think I'm clear of the recall. I bought it last June brand new from a gun store that had to order it, and still have the receipt if i need to send it away.
So the 1st day i took the rifle out it performed just fine. I must have put 100 or so rounds of Winchester white box and Hornady between 147 and 180 grains. Later I decided i wanted to mount an Aimpoint so i had to buy a low profile rail. I bought the HK Low Profile Scope Mount For HK Rifle & Pistols from and it looked great.

I wasn't able to get to the range for a long time after due to school and other responsibilities, but a month or so ago i finally made it out there to test my new Aimpoint on the rifle. I setup everything and got ready to fire... "Click"... It didn't fire. I was using Hornady (The kind that worked last time), Tula and Fiocchi. None of them would fire. I noticed that when i brought the cocking lever home it wouldn't fully close. I figured maybe the mount was on too tight and I removed it that day. It wasn't until yesterday that i was able to get back out and shoot.

I had bought a Hensoldt ZF Model ONE to fill my optic needs. Once again on the range, it did not fire. I took the claw mount off and loaded my Tula mag and fired! One round.... The next round didn't fire. I tested all brands i had, including AE. I noticed most of the rounds have a very light primer strike as well. Some were lighter than others.

Last night i opened it up and decided to do a completely thorough cleaning and noticed there was tons of grease in it. Is that normal? I took everything apart including the bolt group and scrubbed it till it shined. I gave it a little Hoppes to keep it lubed but could that really have been the problem? I'm gonna try to get to the range next week to see if it'll fire but I have serious doubts. I don't wanna send the rifle in if I can avoid it but I've still got about 3 months before the warranty is up. Does anyone have any experience with this issue or advice?

Oh and i checked the Trunnion with help from another thread i saw and it looks fine. I didn't see a single crack so I'm happy that's not a problem.
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Please remember that TULA russian crap has very hard primers,I only use high quality surplus nato brass cased ammo in my german weapons.Yes,get all the grease out. You want these weapons dry inside the chamber area. It sounds like its not going into BATTERY. This means,the bolt head is not seating up against the barrel face,hence no FIRE or light primer strikes.Its bouncing back out of battery. I had this happen to a brand new PTR before. Firing pin could be used,but I doubt it. Clean it dry,especially inside the chamber flutes. Drop the hammer on an empty chamber[ofcourse] and check bolt gap with feeler gauges,between the back of bolt head and fron of carrier. Sounds like a new rifle so clean it and get back to me. If the bolt gap is lower than .010,I would send it back to PTR INC. It may have just been dirty inside the area in question. Sometimes a new HK locking piece can bring bolt gap up a little. There are several things it could be,without me seeing it in person. Let us know. It should have fired all those rounds,firing out of battery can be dangerous if it fires this way. Just my exp. not trying to start an argument with the masses.I do have 0ver 10 years exp . with this platform.
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It wasnt just TULA that wasn't firing. It was Hornady, Fiocchi, American Eagle, and Winchester. What would the odds be that it just doesn't like those brands, especially after it fired 2 of them on day 1. So although it may not be top notch ammo I've kinda ruled out that being the cause.

I have cleaned it hard and only left a little Hoppes there so its not running completely dry. Are you saying i should even remove that?

Also i don't have any feeler gauges. Could you recommend a good place to get some cheap and fast that would be decent?
auto parts store for the $5 feeler gauges and YES,you want these rifles as dry as possible. I only put a tiny dab of TETRA grease on each roller window. This will slow down the metal to metal contact wear.Keep Chamber and barrel dry before every shoot. Ammo is not the issue,Tula is just dirty sticky garbage with hard ass primers in my opinion,either way ,it sounds like a bolt gap or out of battery scenario,but i can,t help if I cant see it.Hope you can send it back,PTR doesnt care if your a month or two past warranty, they have fixed many past the warranty.Their customer service is pretty good at that. Wish i could fix it for you.
You "brought " the carrier handle home? If I read it right you are slowing it down with your hand, or are you correctly slapping the handle down sharply and letting it slam home? Is the magazine fully and I mean fully inserted? They can look that way but if wrench on it they can come right out.. give a HARD palm slap to that mag after it's inserted..

I use synthetic motor oil on my G3 platforms, and give a small dose to the rails and locking lugs and the bolt/bolt carrier interface, as well as the sear/hammer. Keep the chamber dry unless it's in storage or transit
Yes,the hk SLAP is what he needs to do. Dont help it forward. SLAP IT!!
I slap it home...sorry if I confused ya all. Yes the mags are in tight, and i always pull on them a little to make sure its not gonna come out.
Sounds like its not going into battery if its still not firing or striking the primer. I,d have to see it,good luck bro.
Mine did exactly the same thing when it was new, I didn't clean it at first and it would not go int battery for about 10 times out of a 100. Once i reached 100 rounds i never had a problem. I then cleaned it thoroughly still no issues for 1000 rounds now. My bolt gap went from 014 to now a stable .011
Did it start doing this just after the scope mount was installed? Is the mount to tight, deforming the receiver and stopping the carrier from going all the way home?
Did it start doing this just after the scope mount was installed? Is the mount to tight, deforming the receiver and stopping the carrier from going all the way home?
Yes it did start after i installed the 1st low profile mount. The problem has continued after removing it.

I know it probably wont help too much but I'll get some pics of the rifle tomorrow. I'll be sure to get some pics of it at the range next week as well. I try to avoid the range during the weekend cause its so packed. I had pretty much the entire range to myself yesterday and a fun .22 so it wasn't a total loss.
I disassemble all newly obtained weapons and 100% clean them before I take them out.. it saves a lot of grief
Sounds Like you might have pinched the upper if you tightened the mount too tight. This can even happen with real HK products. Will your carrier slide fully forward if you drop it in without the bolt head when the upper is off the lower and muzzle pointing straight down?. If it drags where the tabs are this might be the problem. If it is, all it needs is someone with an HK mandrel to press in to form it back to spec to fix it. Curtis from S&H arms warned me about this once. I'm sure Ghillie Bear or someone can help you out if PTR won't.
Just another good reason to use the factory HK claw mount. The same problem occurs with Tac Star sidesaddle shotgun ammo carriers if you over tighten them, but usually the receiver is so tough it does not permanently injure the gun
I go with pinching the mount too tightm too. Also in needs to be CLEAN.
I use 30w Mobil 1 synthetic LIGHTLY on all my guns, but PTR/HK weapons need real light oiling on the bolt head/chamber areas.
you might try working the bolt vigorously a bunch and see if, if it was pinched a little, it loosens/wears past the bump and starts functioning ok.
Good Luck!!

Sorry it took longer than I said. I've been busy dealing with my graduation stuff. Anyways i got a bunch of pics to TRY and help see what could be wrong. Maybe your more experienced eyes will find something I didn't notice. Also having trouble uploading or linking the pics so I'll just add the direct links.

The Rifle

Trigger group



Cocking lever and gap

They aren't the best pics but it's the best i could do for now. I should also mention that new lever was installed before i fired it the 1st time so i doubt its the problem. It was a simple 3 minute install and really helps me grip it better.

I should have some free time to go out tomorrow and test fire it. If it doesn't fire this time I'm just gonna call in and send it off. I just hope it doesn't come to that.
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Looks like maybe some shiny spots on the carrier were it has been dragging about where the tabs would be where the feet of the mount contact the upper. Did you try to drop the carrier through the upper yet to see if there was any resistance.? Congrats on your graduation by the way!
Must know Bolt gap first,I highly doubt any pinching is going on from a scope mount.I have seen these weapons NOT STAY IN BATTERY if the rollers are the wrong size. If it wont shoot,send it BACK immediatly. The locking lever on the carrier can be an issue also.I would need to see the rifle in order to diagnose the problem.Pics don,t tell anything. just being honest guy,s.
If you installed the new mount before you fired the gun there is no way to know now if it is the problem. This is why I iron sight and break in all such guns before adding optics. I add accessories like this one at a time, saves grief
Looks like maybe some shiny spots on the carrier were it has been dragging about where the tabs would be where the feet of the mount contact the upper. Did you try to drop the carrier through the upper yet to see if there was any resistance.? Congrats on your graduation by the way!
I have and there isn't any resistance that I've noticed, and thanks.

Anyways I got to the range today and of course, It was closed for some sort of maintenance. It's fine since its a very windy day today and I was also gonna sight in my Steyr. I still don't have feeler gauges but I might pick them up on my way back tonight. I figured I wouldn't get much from the pics but it was worth a try.

Also i thought i made it clear that I had installed the 1st mount AFTER my 1st time shooting it. It was this mount, HK Scope Mount | MFI scope mount - HKPARTS.NET , which is a piece of **** that's not even worth 1/10th of the price. I hope that's not against the COC to say lol. I wouldn't think my problems have anything to do with the claw mount since it wont fire even when its naked.
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