Third Party Press

PTR44 Semi-Auto MP44

Doug, Just send your rifle down to Pete ASAP. To diagnose the problem won't cost that much, the expense will come with replacing the worn and or defective PTR parts in the rifle. Get rid of the original Mags that came with the Rifle, the other mags you are using are fine. You can also send some ammo down with the rifle to save on expenses.

My PTR44 is running like a Swiss Watch after getting it back from Pete. :thumbsup:

Dave
 
Ptr44

Mine runs like an AK now, with original OPROD and bolt. I use real mags and the ones from a guy on the old K43 forum. I have shot factory, Prvi and lead cast with no issues.

Doug, Just send it to Pete,



Pat
 
Finally with slight bending and filing of the shell ejector I made the MP44 bolt fit the PTR receiver.

First observation: Size and shape of the ejector have an impact on how the bolt moves into battery. When you look from the back of the rifle, the ejector is in the 7:30 position. Since the bolt has to be tilted for locking, the bolt is undersized compared to the round shape of the receiver, allowing it to move sideways and up/down. If the ejector stands too proud, right before reaching the upper round in the mag, the closing bolt will be pushed up sideways by the ejector towards the ejection port, into a 1:30 position. This will effectively move the bolt away from the mag and may explain why some shooters have to push their mag higher up into the receiver for reliable feeding.

Second observation: The damage referred to in Rommel's post is a combination of the PTR bolt ridge being too narrow for the receiver, the way the MP44 locks into battery and feeding problems. As I stated previously, the internal width of the PTR44 receiver is identical to an MP44 receiver but the PTR bolt ridge is 0.045" narrower than the MP44 ridge. The MP44 locks into battery by means of a cam machined into the op-rod, pushing the rear end of the bolt down once the bolt stops moving after hitting the case head. If you experience an FTF, the jammed round will prevent the bolt from moving forward. At the same time, just like when locking into battery, the cam on the spring loaded op-rod will try to push the rear end of the jammed bolt down. At this point, the ridge at the rear end of the bolt is located where the receiver bottom has the huge slot for the hammer, its weakest spot. The force of the recoil spring pushes the op-rod forward and the op-rod cam pushes the bolt down, trying to force the bolt ridge through the receiver slot. Since the receiver is easily pried apart in the slot area and the PTR bolt ridge is narrower than it should be, the receiver gets mangled as the bolt ridge tries to break through the crescent cutout.
 
Third observation: The MP44 bolt is larger in diameter than the PTR bolt (0.980" vs. 0.963"). On empty chamber the PTR bolt will close but it binds up with a round chambered. If forced close, the MP44 bolt will shave a little bit of brass off the rim of the cartridge. The shaving is on the side of the rim facing away from the mag well, as if something forced the bolt down while closing. I think I can feel a ridge where the bolt snugs into the trunnion. This could push the bolt down just a bit on closing. Either that, or the chamber has been reamed off center and more to the top, which wouldn't be a surprise knowing the "ex-spurts" who already worked on these rifles work before and right after they were sold to the public.
 
interesting

GunKraut said:
Third observation: The MP44 bolt is larger in diameter than the PTR bolt (0.980" vs. 0.963"). On empty chamber the PTR bolt will close but it binds up with a round chambered. If forced close, the MP44 bolt will shave a little bit of brass off the rim of the cartridge. The shaving is on the side of the rim facing away from the mag well, as if something forced the bolt down while closing. I think I can feel a ridge where the bolt snugs into the trunnion. This could push the bolt down just a bit on closing. Either that, or the chamber has been reamed off center and more to the top, which wouldn't be a surprise knowing the "ex-spurts" who already worked on these rifles work before and right after they were sold to the public.
Click to expand...

I don't know that I ever miked a MP and PTR bolt to compare diameter but if the PTR is smaller and the rec. dia. is the same MP to PTR the PTR bolt would be kind of a sloppy fit I'd think.
Interesting in that a PTR I worked on for a guy exhibited similar to what you describe. It was as if the bore and bolt run in the rec. block were not concentric. I thought I could see it when looking through from the rear. But then one sometimes sees what he thinks he ought to see.
After consulting with the owner I lightly chamfered the upper edge of the ctg. head recess on the bolt. That eased the chambering issue it had. That bolt was riding low though so the chamfering was done at the top so it could make its way over the ctg. head as it went into battery.
Pete
 
carrier

GunKraut said:
Finally with slight bending and filing of the shell ejector I made the MP44 bolt fit the PTR receiver.

First observation: Size and shape of the ejector have an impact on how the bolt moves into battery. When you look from the back of the rifle, the ejector is in the 7:30 position. Since the bolt has to be tilted for locking, the bolt is undersized compared to the round shape of the receiver, allowing it to move sideways and up/down. If the ejector stands too proud, right before reaching the upper round in the mag, the closing bolt will be pushed up sideways by the ejector towards the ejection port, into a 1:30 position. This will effectively move the bolt away from the mag and may explain why some shooters have to push their mag higher up into the receiver for reliable feeding.

Second observation: The damage referred to in Rommel's post is a combination of the PTR bolt ridge being too narrow for the receiver, the way the MP44 locks into battery and feeding problems. As I stated previously, the internal width of the PTR44 receiver is identical to an MP44 receiver but the PTR bolt ridge is 0.045" narrower than the MP44 ridge. The MP44 locks into battery by means of a cam machined into the op-rod, pushing the rear end of the bolt down once the bolt stops moving after hitting the case head. If you experience an FTF, the jammed round will prevent the bolt from moving forward. At the same time, just like when locking into battery, the cam on the spring loaded op-rod will try to push the rear end of the jammed bolt down. At this point, the ridge at the rear end of the bolt is located where the receiver bottom has the huge slot for the hammer, its weakest spot. The force of the recoil spring pushes the op-rod forward and the op-rod cam pushes the bolt down, trying to force the bolt ridge through the receiver slot. Since the receiver is easily pried apart in the slot area and the PTR bolt ridge is narrower than it should be, the receiver gets mangled as the bolt ridge tries to break through the crescent cutout.
Click to expand...

Was thinking the pictures posted of the bulged receivers showed the carrier poking down into that cutout not the bolt.
Going on memory though not having a picture in front of me right now.
Pete
 
Bolts

I have 5 original MP43/44 Bolts and a PTR bolt.

Before I knew of Pete, my gunsmith fit two orginsl bolts to run in my PTR 44. He was supposed to just take the best bolt for headspace fit and use that one. He modified two, oh well, no harm, One modified bolt runs perfectly in either my PTR44 or MP44, the other runs well only in my PTR44, where it stays.

When I get chance, I will measure my two untouched original bolts, the modified ones and the PTR bolt. I believe that the only thing that he did to the original bolt was to slightly deepen the channel for the ejector. As I said, one runs flawless in either gun. The other runs flawlessly in the PTR where it stays. I also have one original bolt that came from a German DEWAt where they cut away the bottom part of the bolt face and weld the firing pin hole. Too bad that this bolt cannons be saved.

On the issue where the bolt starts to push through the bottom of the receiver, that happend with PTRs way before any of us started putting original OPRODS and bolt in them. Mine started doing that when I was trying to get it to run with the PTR Oprod and bolt. The situation seems to have stabilized and has not gotten any worse. I am not sure if that is because I no longer use the PTR bolt and Oprod?

Pat

PS, John Andrewski had a deal wih Jerry to make sure the PTRs ran. I sent my first one to him 3 times, then Jerry exchanged it. The second one went once or twice until I gave it to my local Gunsmith with an original bolt and Oprod. Jerry told me that John stopped working on them. No two guns were alike, dimensions on them were all over the map making it extremely difficult to troubleshoot and repair.




shortfal said:
I don't know that I ever miked a MP and PTR bolt to compare diameter but if the PTR is smaller and the rec. dia. is the same MP to PTR the PTR bolt would be kind of a sloppy fit I'd think.
Interesting in that a PTR I worked on for a guy exhibited similar to what you describe. It was as if the bore and bolt run in the rec. block were not concentric. I thought I could see it when looking through from the rear. But then one sometimes sees what he thinks he ought to see.
After consulting with the owner I lightly chamfered the upper edge of the ctg. head recess on the bolt. That eased the chambering issue it had. That bolt was riding low though so the chamfering was done at the top so it could make its way over the ctg. head as it went into battery.
Pete
Click to expand...
 
Last edited:
Waffentag said:
I have 5 original MP43/44 Bolts and a PTR bolt.

When I get chance, I will measure my two untouched original bolts, the modified ones and the PTR bolt.
Click to expand...

Pat, by all means, please take some measurements of your PTR and MP44 bolts. Please measure the bolt diameter at various places but also the width of the bottom ridge at the back of the bolt.


Waffentag said:
I believe that the only thing that he did to the original bolt was to slightly deepen the channel for the ejector.
Click to expand...

I guess you mean "ejector"? That would support my observation that the ejector slot in the PRT bolt is cut deeper than the respective MP44 slot, allowing the PTR ejector to be taller than an MP44 ejector, thereby causing interference if an MP44 bolt is used in a PTR receiver.


Waffentag said:
On the issue where the bolt starts to push through the bottom of the receiver, that happend with PTRs way before any of us started putting original OPRODS and bolt in them. Mine started doing that when I was trying to get it to run with the PTR Oprod and bolt. The situation seems to have stabilized and has not gotten any worse. I am not sure if that is because I no longer use the PTR bolt and Oprod?
Click to expand...

You are absolutely correct, the problem is caused by the original PTR44 bolt because its bottom ridge is too narrow. Using an MP44 bolt (which also necessitated use of an MP44 op rod) was an improvement because the wider bottom ridge of the MP44 bolt made it less likely for the bolt to be pushed through the hammer slot in the receiver.

I invite all members who had problems with their PTR44 to chime in and share their story. I think we are getting close to nailing down the root cause of the PTR jamming/FTF/FTE problem. Maybe the solution is as simple as removing the width restriction in the back of the PTR receiver and adding material to the bottom ridge of the PTR bolt to make it wider. Other problems have been reported such as snapped off op rod ears but maybe these are secondary effects that can be traced back to bolt malfunction.
 
Rommel said:
Doug,
Look at "PICS" on #41,#42
Is there anything going on with your rifle in this location?

http://www.k98kforum.com/showthread.php?9416-PTR44-Semi-Auto-MP44/page5
Click to expand...

There doesn't appears to be anything noticeably wrong (some sharp edges though) with the rifle in that location from what I can tell. Comparing my photos here and the ones you directed me to, my lower receiver looks much better. The bolt looks to clear that area just find. There is no noticeable drop of the bolt into the area where the roundr cut is. However, the rear of the op feel likes it sort of "climbs up" slightly when pushing the bolt forward into battery while crossing that section.

DSC00307.jpg

DSC00304.jpg

Reading the other posts and the possible causes of the PTR's FTF FTE issues, it looks like there is a pretty good agreement on what some of the general problems are caused by. Fixing it any further is beyond me. I'm just going to send the rifle down to Pete to have him work on it. I'm going to ask him to fit my original MP44 op rod and bolt into the rifle and do any other improvements he feels necessary now or that will help preventative future concerns.

Thanks for all the useful info. guys !!!

Doug
 
Pete did a laundry list of fixes and improvements on it for me:

1. Opened up rear receiver to get my original WW2 MP44 bolt and op rod to go in. Best part is NO modifications needed on those parts to get them to function and the original WW2 bolt head spaced adequately. Works perfect with NO malfunctions.

2. Placed the PTR44 bolt and op rod back in the rifle after opening up the rear of the receiver and the PTR parts still work perfectly as well with NO malfunctions.

3. After determining that both sets of bolts and op rods worked, he tested all 3 different types of reproduction mags. I have to see it any of them fed improperly and cause problems. Each mag worked and didn't caused any misfeeds.

4. Re-welded the bottom of the lower receiver and closed the gap to where only the necessary clearance is needed for the hammer. Pete pretty much determined that this was my primary problem with the rifle jamming. As a lot of the PTR44 people know, mine worked great out of the box for a long time. However, over time that receiver section likely just kept wearing away to where it then started to jam consistently, starting last year.

5. Installed a sight blade from a Mauser in the front sight tower as the one I had was defective. Had to gradually shave off material from the new blade to get it to the correct height. Took it to the range a few times to accomplish this.

6. Fixed front sight tower from being slightly canted to the left. Reamed rear pin hole and manufactured new pin to properly hold the front tower in place.

7. After working out the sight issues, Pete dialed in the rifle and centered it at 100 yards with a 6 o'clock hold.

8. Redid rear sight pin that was mushroomed out at time of original installation.

9. Installed a urethane buffer to help keep carrier from having metal to metal contact with the receiver cap.

10. Fixed ejection port cover so it closes and opens properly. Mine would stick a lot of the time when pulling back on the bolt and not always open.

~WHEW~ ... for all I know, he'll find more to do. LOL !!!

I can't wait to see and shoot it. I'm totally stoked.

Doug
 
he is a true master, proud to say I have had many a fine conversation with him.

jerry had a few left over problem PTR's last year for 5K I almost bought one just to have Pete tinker with
 
I'm tempted to send mine to him for the lower receiver repair and to check it out- the original PTR oprod and bolt seem to be working fine in mine though. I don't have an original oprod and bolt.
 
mrfarb said:
I'm tempted to send mine to him for the lower receiver repair and to check it out- the original PTR oprod and bolt seem to be working fine in mine though. I don't have an original oprod and bolt.
Click to expand...


plenty of rods and pistols around even repro's ( could be ssd extra's?) bolts are hard to find at a fair price last couple went for over $500, as I posted else where if I owned a PTR 44 it would go straight to Pete
 
Adventures in WECSOGing the PTR

My PTR op rod ears broke off a while back. Was able to get another PTR op rod to replace it. I didn't feel good about shooting with it, so I considered doing things right. After some wincing and gnashing of teeth (caused the over the prices), I found and purchased, over time, an original MP44 op rod, bolt, and ejector on Gun Broker. Thanks to some great articles by you guys here, and on other sites, I got a finer insight as to what was going on in the MP/PTR's inner workings. I removed the blocking tabs at the rear of the receiver a while back and put in the op rod and bolt. The bolt just rode too high in the receiver with PTR's ejector in it, and the front of the bolt fit way too tight when closed. Well what next? Some more time passes. After reading how to remove the locking block and ejector thanks to you guys articles, I mulled over this for a time and let things sit. So, after a bit more time, and with some consternation, I took out the retaining pins, and tapped out the ejector and locking block and looked around in the receiver. It was a bit claustrophobic, but I installed the MP44 ejector, replaced the locking block, and then put in the op rod/bolt. Everything just FIT FINE. No slop, op rod/bolt bolt rode back and forth great, only a little tight closing in the locking block area. I drilled the ejector in place and reinstalled the pins. Went out and shot it several times the next day and me oh my. It just shot like it should have in the first place. No FTFs, No FTEs No anomalous sputterings. After I got home, I checked everything out and all was fine, and the test firing did a little set back on the locking block so the bolt now closes smooth as butter. Thanks all for the gleaned information I used. All's not done to it yet, but I now have a real shooter after 6 years.
 
A working PTR is a great thing

Good, write up. I did about the same thing. Mine now runs like an AK.

There are only a few of the 200 that are now "all better"





[I[/I]
lyfrok said:
My PTR op rod ears broke off a while back. Was able to get another PTR op rod to replace it. I didn't feel good about shooting with it, so I considered doing things right. After some wincing and gnashing of teeth (caused the over the prices), I found and purchased, over time, an original MP44 op rod, bolt, and ejector on Gun Broker. Thanks to some great articles by you guys here, and on other sites, I got a finer insight as to what was going on in the MP/PTR's inner workings. I removed the blocking tabs at the rear of the receiver a while back and put in the op rod and bolt. The bolt just rode too high in the receiver with PTR's ejector in it, and the front of the bolt fit way too tight when closed. Well what next? Some more time passes. After reading how to remove the locking block and ejector thanks to you guys articles, I mulled over this for a time and let things sit. So, after a bit more time, and with some consternation, I took out the retaining pins, and tapped out the ejector and locking block and looked around in the receiver. It was a bit claustrophobic, but I installed the MP44 ejector, replaced the locking block, and then put in the op rod/bolt. Everything just FIT FINE. No slop, op rod/bolt bolt rode back and forth great, only a little tight closing in the locking block area. I drilled the ejector in place and reinstalled the pins. Went out and shot it several times the next day and me oh my. It just shot like it should have in the first place. No FTFs, No FTEs No anomalous sputterings. After I got home, I checked everything out and all was fine, and the test firing did a little set back on the locking block so the bolt now closes smooth as butter. Thanks all for the gleaned information I used. All's not done to it yet, but I now have a real shooter after 6 years.
Click to expand...
 
Good for you !!! It seems to be the staple thing to do to get the op rod and bolt replaced for either a spare or as a replacement for failed PTR parts. Many people here have done it, including myself. I was lucky enough to get someone extremely knowledgeable to work on my rifle. Thanks Pete !!! I've only shot it a couple times since I got it all back together, but each time it works ... I grin. That type of work/repairs will also add a premium selling point to the rifle as well one day.

Have fun !!

Dog
 
Parts

Just remember with the OPROD that RECON changed the bolt handle as one of the Compliance parts. There was a list on the old K43 forum. I recall talking to Jerry that he had actually had more than required?

Pat

PS, he still sells all the compliance parts, I bought a set jsut to have it.
 
After Pete did his Magic on my PTR44 it's nice to know it will keep up with the rest of the Family.



Rifle has been flawless after the fix.:thumbsup:
 
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