PTR44 Semi-Auto MP44

So I seem to be having an issue maybe? I got one of the "problem guns" from Recon a couple years back. It had a broken bolt so I got it for a discount.. When I got it in my hands there was the front end of a case stuck in the chamber. I figured that happened when the bolt gave way.
I put in an original bolt and op rod, I live fired it maybe 80 rounds. (Factory Graf "Hornady" stuff). It seemed to run just fine. Most of the brass looked totally fine,, but some of the brass looked sketchy! A handful appeared to show sings of stress/separating.
Of the four bad ones, three didn't measure any longer than the unfired brass, but the case that showed the most deformation showed a .03 stretch in OAL from the others it also has a noticeable hole in the side towards the base. I also noticed a slight bulge in the receiver along the charging handle slot from the handle after it had traveled rearward during cycle about 3/4".
Curious that I only had a problem with such a small percentage of the rounds fired.
Has anyone had any problems with the Hornady-Graf 7.92x33 stuff?
Also where can I get a 7.92x33 headspace gauge ?
 
StG44 said:
...I put in an original bolt and op rod, I live fired it maybe 80 rounds. (Factory Graf "Hornady" stuff). It seemed to run just fine. Most of the brass looked totally fine,, but some of the brass looked sketchy! A handful appeared to show sings of stress/separating.
Of the four bad ones, three didn't measure any longer than the unfired brass, but the case that showed the most deformation showed a .03 stretch in OAL from the others it also has a noticeable hole in the side towards the base. I also noticed a slight bulge in the receiver along the charging handle slot from the handle after it had traveled rearward during cycle about 3/4".
Curious that I only had a problem with such a small percentage of the rounds fired.
Has anyone had any problems with the Hornady-Graf 7.92x33 stuff?
Click to expand...

Yes, I observed early signs of head separation with Hornady brass:
http://www.k98kforum.com/showthread.php?9482-Case-Splitting-in-PTR44
I hope it was just a bad batch. Haven't had any problems with PRVI brass or DYI cases made from 8x57 Mauser shells.
 
005_1.jpg
Case on the bottom is unfired.
Second shows slight stress towards base.
Third show stress and hole by base and neck
Fourth from bottom is stretched whith larger hole and pronounced bulging towards base.
Fifth shows crack half the circumference of the neck.
Out of 80 rounds the rest looked totally fine and normal.

Top seperated case is what I found in the chamber when I got received the rifle.
 
chamber?

StG44 said:
View attachment 122271
Case on the bottom is unfired.
Second shows slight stress towards base.
Third show stress and hole by base and neck
Fourth from bottom is stretched whith larger hole and pronounced bulging towards base.
Fifth shows crack half the circumference of the neck.
Out of 80 rounds the rest looked totally fine and normal.

Top seperated case is what I found in the chamber when I got received the rifle.
Click to expand...

I'd be interested in seeing a chamber cast of the chamber of that rifle.
You could mike the cases just below the body/shoulder radius and compare to an unfired case and see how much the case is enlarged in firing. Same thing where it's swelled just forward of the thick web area.
Could be the chamber is oversize which might cause more problems than a headspace issue. Could be just a ammo issue too. I never have had any Hornady ammo but have shot much FNM that is (said) to be same as Privi. Half or more cases need trimming (I trim to 1.290) some as much as .030 but have never had a case do anything funny other than one that separated. It had been reloaded at least 6 times though.
I know from experience that the MP44's often have long headspace that unless really long, .010 or more over GO, does not seem to cause any problems even with cases reloaded many times.
I would not think the PTR's would behave differently.
Pete
 
questions??

StG44 said:
So I seem to be having an issue maybe? I got one of the "problem guns" from Recon a couple years back. It had a broken bolt so I got it for a discount.. When I got it in my hands there was the front end of a case stuck in the chamber. I figured that happened when the bolt gave way.
I put in an original bolt and op rod, I live fired it maybe 80 rounds. (Factory Graf "Hornady" stuff). It seemed to run just fine. Most of the brass looked totally fine,, but some of the brass looked sketchy! A handful appeared to show sings of stress/separating.
Of the four bad ones, three didn't measure any longer than the unfired brass, but the case that showed the most deformation showed a .03 stretch in OAL from the others it also has a noticeable hole in the side towards the base. I also noticed a slight bulge in the receiver along the charging handle slot from the handle after it had traveled rearward during cycle about 3/4".
Curious that I only had a problem with such a small percentage of the rounds fired.
Has anyone had any problems with the Hornady-Graf 7.92x33 stuff?
Also where can I get a 7.92x33 headspace gauge ?
Click to expand...
You can get HS gauges from Pacific Tool and Gauge or JGS(Jims Gun Shop) JGS worked with me real fine on a MP44 chamber reamer I had made to other than CIP spec.
That distortion at the forward part of the PTR slot seems to be common to those rifles. I've worked on several and all had it to some degree. Interestingly a semi I built on a somewhat damaged PTR rec. I got from Recon shows no sign of it even after over 3 years of shooting. It lives with original MP44 bolt/carrier though. Could be some unseen dimensional flaw in the PTR bolt/carrier could be the cause. I'm for sure open to opinions re that.
See my other reply re ammo, HS. etc.
Pete
 
Anybody have a disconnector break?

Anyone have this happen? Maybe I did something wrong in that I re-crimped some PPU ammo because the original crimp, if there is one, was really not too tight. I've had a couple of failure to feeds after installation of an original bolt and op-rod (and even more before with the PTR parts assumably). Both were because the bullet was pushed up into the case slightly. Only had to wiggle the op-rod handle a bit and they slid in. But, when this fiasco happened, I had a quadruple fire and a case separation. I've had several double fires over time, though nothing like that. These double fires always happened after I was squeezing the trigger slowly. There was a point in the pull when the hammer released and I got the double fire and my trigger finger seemed to just stay in that spot. It was all in a blink of an eye. Maybe a kind of bump fire? This never happened with a conscious quick full pull of the trigger. Looking at the disconnector it seems to be made akin to the PTR op-rod that broke. Bad heat treating again? The re-crimped PPU seemed to fire the same, no signs of any overpressure, ejections are the same. I don't know, the rifle really shoots and functions positively now otherwise.
 

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lyfrok said:
Anyone have this happen? Maybe I did something wrong in that I re-crimped some PPU ammo because the original crimp, if there is one, was really not too tight. I've had a couple of failure to feeds after installation of an original bolt and op-rod (and even more before with the PTR parts assumably). Both were because the bullet was pushed up into the case slightly. Only had to wiggle the op-rod handle a bit and they slid in. But, when this fiasco happened, I had a quadruple fire and a case separation. I've had several double fires over time, though nothing like that. These double fires always happened after I was squeezing the trigger slowly. There was a point in the pull when the hammer released and I got the double fire and my trigger finger seemed to just stay in that spot. It was all in a blink of an eye. Maybe a kind of bump fire? This never happened with a conscious quick full pull of the trigger. Looking at the disconnector it seems to be made akin to the PTR op-rod that broke. Bad heat treating again? The re-crimped PPU seemed to fire the same, no signs of any overpressure, ejections are the same. I don't know, the rifle really shoots and functions positively now otherwise.
Click to expand...


YES !!! That happened to my rifle just a few months ago. Dunno if it was heat treating or what, but very likely. I was firing the rifle normally and not rapid fire or bump firing it. I had the lower sent to shortfal and he fixed it for me. He ordered an original disconnector from oversees to replace it. The rifle works great now.

I've also had "bump fire" like double fires a couple of times prior to shortfal fixing the rifle. I associated the double fires with slow meticulous shooting amounting to an unintended bump fire action. I actually have a video of it happening and will post it here if I still have it. I doubt your ammo had anything to do with it. I've heard of other disconnectors breaking on these rifles over the years. Get an original disconnector as a replacement part. They are on GB every now and then and otherwise not terribly difficult to find.

At least the 1940s Germans made these rifles solidly. I'm much less impressed with SSD's version ... :facepalm:

Doug
 
disconnectors ?

lyfrok said:
Anyone have this happen? Maybe I did something wrong in that I re-crimped some PPU ammo because the original crimp, if there is one, was really not too tight. I've had a couple of failure to feeds after installation of an original bolt and op-rod (and even more before with the PTR parts assumably). Both were because the bullet was pushed up into the case slightly. Only had to wiggle the op-rod handle a bit and they slid in. But, when this fiasco happened, I had a quadruple fire and a case separation. I've had several double fires over time, though nothing like that. These double fires always happened after I was squeezing the trigger slowly. There was a point in the pull when the hammer released and I got the double fire and my trigger finger seemed to just stay in that spot. It was all in a blink of an eye. Maybe a kind of bump fire? This never happened with a conscious quick full pull of the trigger. Looking at the disconnector it seems to be made akin to the PTR op-rod that broke. Bad heat treating again? The re-crimped PPU seemed to fire the same, no signs of any overpressure, ejections are the same. I don't know, the rifle really shoots and functions positively now otherwise.
Click to expand...

Not long ago I replaced one for a PTR owner with a original off GB. I also made a repair that limited the trigger travel such that the sear could not be pushed high enough for the hammer to strike the disconnector when cycling.

A good idea to carefully examine the disconnector pin. Some are undersize and not peened in very well. A new one made from drill rod or Stress Proof steel can be needed.

Had another PTR that had an issue with the hammer not being caught reliably by the sear if the shooter kind of "feathered" the trigger. Adding some travel to the disconnector fixed that.
Pete
 
Thank you guys for the responses. Makes scratching my head tolerable with some of the fine insight given. Got an original disconnector ordered, so here goes.
 
mostpeople said:
What's the word on the new import PTR-44's?
Click to expand...

I haven't seen any changes to the web site or received any additional emails from the importer/manufacturer. If the idea is to move the project to the USA to produce them (as was mentioned previously) there is nothing about that on their site that I can find. As to importing them, I seriously doubt you will ever see these rifles (or other SSD made products) make it back to the USA.
 
That's good because it would self destruct! I know I sound like a broken record.....

But I'm weird I guess because I expect things to work.
 
Semi Built

Pete, Good question, Look at what parts kits go for now. I think that you will have a wide variety on quality of the builds. Also, I understand that PTR went through the whole ATF approval process?

Pat




shortfal said:
A quote I probably use too much. "If you did not know it was true, you would not believe it".
So if one of them is worth that kind of money, how much is a nicely built original parts semi rifle worth?
I guess it's not what either is worth it's what someone in an auction will PAY.
Pete
Click to expand...
 
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