PTR-91 at the range

[Panzerschwein]

Okay guys, as some of you may know I've been having some issues with my PTR-91 GI. The steel surplus magazines I have for the gun were falling out during recoil, so today in the mail I received a new magazine catch donated by a member from a different forum.

I got my new magazine catch installed today and went to the range with all 12 of my steel magazines, each loaded with 9 rounds for a total of 108 rounds.

I experienced one double feed type jam. An empty case got stuck vertically in the ejection port, the bolt was wedged open and upon removing the magazine a live round also came out. The mouth of the empty case was mangled, so I'm guessing maybe the fired case didn't extract all the way, the bolt went forward stripping a live round from the magazine and when the bolt tried to close the stuck cartridge's case mouth smashed into the breach face and got mangled. I'm not sure what would cause this. The next rounds in the magazine fed fine so I'm not sure weather to chalk it up to the break in period (so far I've fired 310 rounds of ammo including today), a bad mag, and underpowered round, or what. I marked the mag with my car keys for later ID. I fired about 5 more mags after that with 0 issues.

Oh, and none of the magazines fell out!!! I think the new magazine catch definitely solved that issue. I'll be on the lookout for any more double feeds like I had, but so far the gun is shooting well and my accuracy is improving. I have been shooting in a 25 yard indoor range, but want to get out to the nearby 300 yard rifle range soon.

I'd like some input on the malfunction I had today. What would cause that type of failure? Do you think it's gun or magazine related, or maybe just a weak round? Any feedback would be greatly appreciated. I'd like to get this gun functioning 100% if at all possible.

Thanks guys!

 

[stubbicatt]

With magazines as inexpensive for that rifle as they are, I would mark that one and put it in the "suspect" box, and use others in its stead. It does sound like a failure to eject, however. If you want to verify that the trigger pack is sufficiently snug to the receiver, clean the rifle well, reassemble, and turn it over. While looking up through the magazine well, slowly retract the bolt, and watch as the ejector rises into the bolt cutout. There should be very little clearance between the nose of the ejector and the bottom of the corresponding slot in the bolt. If that clearance is too great, you will experience ejection failure.

FWIW

ETA: BTW, an unacceptable buildup of crud in the slot is unlikely due to the action of the nose of the ejector acting as a scraper of sorts, but if you notice quite a depth of smuts in there, that is also an indication of ejector malfunctions.

 

[briansmithwins]

FTEject can also be caused by short stroking where the bolt head didn't come back far enough to activate the ejector, but it did make it back enough to start loading another cartridge.

What ammo are you using?

BSW

 

[Panzerschwein]

FTEject can also be caused by short stroking where the bolt head didn't come back far enough to activate the ejector, but it did make it back enough to start loading another cartridge.

What ammo are you using?

BSW

I have been exclusively using ZQI 7.62x51mm ammo in the rifle. I'm not sure if it's very good, but the price is right at Wal-Mart for it!

I checked my ejector and it does seem to make nice contact with the bolt as it slides back. I'm not sure how much spring pressure there is supposed to be on it, it isn't hard to push the ejector in.

I'm really hoping it was just a fluke, I love the gun so far but hope it doesn't have continuing issues because I plan to use it as my main defense rifle.

 

[ttarp]

ZQ1 is pretty good ammo, I've fired quite a bit of it in my PTR without any trouble.

Stubbicats suggestion about the suspect mag box is a good idea, I have one of my own.

 

[dogmush]

Is this one of the mags that fell out?

An RDB will extract and eject a round without the extractor installed. (I've done it) Chamber flutes are cool. I can't really help you troubleshoot that, because neither of my RDB rifles have ever failed to kick the spent case out. The design has some quirks, but keeping the spent p brass in the gun, or even near it, isn't one of them.

Shoot it more, see if it's the mag.

 

[jeff-10]

ZQ1 is pretty good ammo, I've fired quite a bit of it in my PTR without any trouble.

It's pretty much all I fire from my PTR 91. No failures at all.

 

[Panzerschwein]

Yeah I won't be using the same magazine though. If the problem happens again, I'll go from there. It just made me sad when it happened, it was running like a champ! Well, minus the mag drop issue which is now fixed.

 

[briansmithwins]

The ejector lever doesn't have a stiff spring and moves easily under pressure. The ammo should be GTG too.

Unless the rifle is totally dry or the bolt carrier is binding, I'd tend to agree about the magazine.

BSW

 

[Panzerschwein]

The ejector lever doesn't have a stiff spring and moves easily under pressure. The ammo should be GTG too.

Unless the rifle is totally dry or the bolt carrier is binding, I'd tend to agree about the magazine.

BSW

Okay great! I'll thoroughly clean the rifle tonight and take it to the range tomorrow and hopefully it runs OK.

 

[dvdcrr]

You need to clean the chamber flutes with solvent and a 44 cal bronze brush.

 

[briansmithwins]

You need to clean the chamber flutes with solvent and a 44 cal bronze brush?

I don't think clogged flutes would do that. Ripping brass in half, yes.

Cooldill, what's your bolt gap? That also plays into functioning. Spec is 0.1 to 0.5mm.

BSW

 

[Panzerschwein]

I don't think clogged flutes would do that. Ripping brass in half, yes.

Cooldill, what's your bolt gap? That also plays into functioning. Spec is 0.1 to 0.5mm.

BSW

I'll have to check tomorrow, I've also been sure to keep the chamber of this rifle very clean.

 

[stubbicatt]

For cleaning the chamber fluting I purchased a couple of unique brushes from Adam at HK parts dot net. Unlike most brushes which one inserts into the chamber, and then rotate around in there to clean, these are strictly "in and out" sort of brushes which dig into the crud in the fluting, and help remove it. I follow with a 45 bore mop to remove the loosened crud. They are not cheap, but I am still using my first one purchased about 15 years ago now, so they last a very long time.

Typically I dry brush, and haven't found a need for solvent in this application, other than the residual solvent that might leak around the bore guide.