Anyone Having 4th Round Jams with their Pardini SP New?

I help coach a college team, and they have 5 Pardini SP New's.  I've been working with Pardini USA to fix problems we've been having with 4th round jams.  I have improved things by carefully fitting new extractors, but the problems have persisted despite replacing magazines, recoil springs, and buffers.  I was going to send a couple down to Pardini to look at after the Collegiate National Championships last March.  Well, COVID hit, they canned the Nationals, and we've been locked out of the range ever since.  It's quite likely we will not have access to the range (or the pistols) for many more months.  

I have some ideas about what is going on & how to fix it, but I can't do any test firing.  I'm looking for a few "beta testers" to work with.

If you have a Pardini SP New (with the O-ring buffer in the bolt), and have had persistent 4th round jam issues, I would be delighted to work with you to try to fix the problem.  Before we get serious, there are a number of things you can try that can often help.  I've posted some info on the TargetTalk Olympic Pistol forum on things to try first:


http://www.targettalk.org/viewtopic.php?f=4&t=27446&p=292149p292149

Based on the bullseye league I shoot in, there are likely to be a lot more Pardini owners on this forum than on TargetTalk. If you've tried all the usual fixes and are still having problems, PM me and I'll do what I can to help.  In return, all I ask is that you do some test firing and take notes to help with my research.

Thanks!

Interesting. I’ve had no such issues and haven’t heard of too many issues with .22. I think you’re in the right place though!

I had 4th round jam with my HP but not SP. it was damn near 100% of the time and in all magazines. The fix was replacement of the 13 o- rings in the buffer. Not a single malfunction since

orpheoet wrote:Interesting. I’ve had no such issues and haven’t heard of too many issues with .22. I think you’re in the right place though!

My wife shoots an SP (Old) and never had a problem until her magazines got dirty (~2003 vintage).  That was an easy fix.  I have an SP New with the buffer in the frame, and never had a problem either. (vintage ~ 2008)  All of the pistols that have the problem are SP New's with the O-ring buffer, but only some of them.  The team pistols are from early 2017.  

I need more data points...

James Hensler wrote:I had 4th round jam with my HP but not SP. it was damn near 100% of the time and in all magazines. The fix was replacement of the 13 o- rings in the buffer. Not a single malfunction since

That has definitely helped many pistols.  I haven't figured out the physics, because the buffers don't come into play until well after the case has hit the ejector tab.  My suspicion is that the added jolt with a dead buffer causes the rounds in the magazine to shift forward, but that's only a theory.

It would kelp a lot more if you told us ammo, and provided pictures of the stoppage.

gwhite wrote:

James Hensler wrote:I had 4th round jam with my HP but not SP. it was damn near 100% of the time and in all magazines. The fix was replacement of the 13 o- rings in the buffer. Not a single malfunction since

That has definitely helped many pistols.  I haven't figured out the physics, because the buffers don't come into play until well after the case has hit the ejector tab.  My suspicion is that the added jolt with a dead buffer causes the rounds in the magazine to shift forward, but that's only a theory.

I believe it is a timing issue and the pistol cycle is way to fast. When the new O-rings are installed they absorb more and it slows down the timing! My 2 cents

Wobbley wrote:It would kelp a lot more if you told us ammo, and provided pictures of the stoppage.

I don't have any pictures, but basically, the case from the 4th round fails to eject cleanly, and gets trapped in the action while the 5th round attempts to feed.  The team shoots mostly CCI standard velocity in the Pardinis, although some of the pistols will cycle Aguila standard velocity as well.  I know a couple people who've had the same problem, and I believe they have tried other ammo without success.  I've had lengthy exchanges with Pardini USA on this, and they never mentioned ammo as a likely culprit.

The jams only occur after the 4th round.  With fresh buffers and a properly tuned extractor setup, they may go a few hundred rounds after a cleaning without a problem, or they may fail within 50 rounds or less.  The problems actually seem to be worse not long after a cleaning.  I think the dirt slows it down just a tad, and that seems to help, but it's hard to say for sure.

With the description provided, I’d look at magazine sprung tension.  It is very likely the Mag springs may not be providing enough up pressure on the bolt to slow it down.

You have multiple things happening sequentially that as James mentions results in shifted timing. You are right in that buffer and O rings come into play after seemingly the roundis ejected. However, you need to understand the timing is very quick, so even though you think the round hit the ejector and extractor flipped it out...it did not leave your gun yet...before the bolt slams back into it. Slow things down -- round fires, action opens, extractor catches shell and carries it into ejector, ejector pushes shell to the side and with momentum shell is supposed to fly out of a gun. Now the action splits 1) shell is supposed to keep flying 2) bolt keeps moving back, slowing down by loss of momentum and recoild spring as it reaches buffer and O rings mechanism that cushion the momentum completely and then the recoil spring sends the bolt back. At that time it picks up new round, slowing down on the way and driving/slamming round into barrel. Your timing seems to be shifted where #2 above happens too fast and so the shell in #1 did not leave the gun yet as bolt is slamming back into it. You need to slow down the timing. I would suggest new recoil spring or figure out with Pardini a stiffer spring. New buffer, new O rings. Even the material of O rings will play a role in cushioning and slowing action. 


Now you will ask why on 4th round. The catch here is that it seems like your failure is progressing as you shoot. Why? Simple - your gun warms up. Your timing is OK until the gun warms up and spring with buffers losen up. Yes, buffers also losen up after slide slams into them few times.
Opposite is true if your fails would be on first rounds only - spring too stiff and with warming of the gun spring losens up and timing sets right -- this I learned thoroughly on 1911 conversion, but mechanisms at work are the same.


It is very likely you need to tune not the mag/extractor, etc.., but the timing of the gun. Especiallyif you have same issue with all mags, that tells you it's not the mag and not the feeding. Extraction good first 3 round means not extraction. Timing!



Yev

I believe that the reason it's happening on the 4th round is that the bullet of the 5th round is popping up and hitting the case like this:



This picture is static (non-firing), and is taken with the bolt pullet back to a point just before the case hits the ejection tab.  Pistols where the bullet does not deflect the case don't have 4th round jams.  Both of the older SP's my wife & I have actually have a gap under the fired case above the bullet of the 5th round.  You can make a pistol more jam resistant by making sure the extractor has a good grip on the fired case, but eliminating the deflection entirely has been my goal.  As I said, I have some ideas on that matter, but I need people who can test them.

Ahhh, now this is different. Does it happen to all mags in same way? If yes then your mag catch may be cut too high and needs to be either lowered or crimp down and file mag top. It is common for last round to be angled upwards in many guns of different calibers.

Tripscape wrote:Ahhh, now this is different. Does it happen to all mags in same way? If yes then your mag catch may be cut too high and needs to be either lowered or crimp down and file mag top. It is common for last round to be angled upwards in many guns of different calibers.

The team pistols that have this problem have been extensively tested with multiple new magazines.  I've even tried reversing the magazine spring, and that has no particular effect on the problem.

A really dirty magazine will do it.  If the top front gets covered with crud, it can tilt the follower back enough to cause a problem.  My wife's SP (Old) had this problem.  The 5th bullet would hit the 4th case, but as soon as I cleaned it, the deflection dropped and the problem went away.  After I installed a new follower, it got even better, with a nice gap under the 4th case.  That was 2 1/2 years ago, and she hasn't has a problem since.

Part of the problem is that when the bolt comes back, it's dragging on the top of the rim of the 5th round, which wants to tip the bullet up.  Friction between the top of the follower and the bottom of the rim resists this.  New followers have a slightly rough finish on top, and that helps hold the bullet down.  Once that roughness has been polished down by many thousands of rounds, it's not as effective

So maybe sacrifice a magazine and try to crimp it down more on top, but do not move ejector position.

Don't stop examining the "extractors'.
I was having stove pipes three years ago with a new SPBE and checked 
the mags with indicators and also used them in my 30 year old SPE.
I decided the issue was most likely the extractor.
I polished all surfaces and ensured the spring was functioning as it should.
Still got stove pipes. I had the extractor out of the old SPE and after seeing it was an 
exact duplicate of the new one in the SPBE I swapped them.
I never had another stove pipe.
the new extractor worked well in the old SPE too.
Now I can't tell you what the real difference was other than the old extractor 
had become highly polished on ever surface that contacted the brass from years of use.
This could possibly help you I hope.

G

Gary Collette wrote:Don't stop examining the "extractors'.
I was having stove pipes three years ago with a new SPBE and checked 
the mags with indicators and also used them in my 30 year old SPE.
I decided the issue was most likely the extractor.
I polished all surfaces and ensured the spring was functioning as it should.
Still got stove pipes. I had the extractor out of the old SPE and after seeing it was an 
exact duplicate of the new one in the SPBE I swapped them.
I never had another stove pipe.
the new extractor worked well in the old SPE too.
Now I can't tell you what the real difference was other than the old extractor 
had become highly polished on ever surface that contacted the brass from years of use.
This could possibly help you I hope.

G

I think I've done all I can in the extractor area.  I've attached some notes on SP Extractor tuning I put together after quite a bit of experimenting.

gwhite,
I read your very detailed instructions on Pardini extractors.
Your are very very detailed in your examinations and my hat is off to you.
I will be following this tread and hope to learn some from your observations.
G

Gary Collette wrote:gwhite,
I read your very detailed instructions on Pardini extractors.
Your are very very detailed in your examinations and my hat is off to you.
I will be following this tread and hope to learn some from your observations.
G

Thank you.  

Besides coaching, I'm the defacto team "armorer".  After over 40 years of engineering work, I'm kind of rabid about documentation.  I find it saves a lot of time and head scratching when I have to revisit a problem.  Especially because my memory isn't what it used to be. Someday I won't be around and somebody else will need to take care of all the hardware.  In the meantime, if it helps others, that's great too.

I read your extractor instructions and just like Gary my hat off to you!!!

Tripscape wrote:I read your extractor instructions and just like Gary my hat off to you!!!

Thanks!  

Flattery will get you somewhere...  I've been meaning to update my notes on the Pardini O-ring buffers for a while, and I had some time over the Holiday to do that (see attached).  

Replacing the buffer O-rings can (at least for a while) help with the 4th round jam problem.  Based on info on this forum, it looks like Pardini has changed their O-ring material sometime in the last year or so.  If my suspicions are correct, the newer ones will last a lot longer.

Any updates on what you've learned about this?  Do you have any more of your documents to share?  I'm having some occasional FTEs on a new to me (and recently tuned up) SP. Hopefully it's more tractable than your issue as it happens with multiple mags and different shots. The extractor was quite dirty so cleaning that is my next attempt to fix. Pardini also suggests new recoil spring and buffers.

kayakr wrote:Any updates on what you've learned about this?  Do you have any more of your documents to share?  I'm having some occasional FTEs on a new to me (and recently tuned up) SP. Hopefully it's more tractable than your issue as it happens with multiple mags and different shots. The extractor was quite dirty so cleaning that is my next attempt to fix. Pardini also suggests new recoil spring and buffers.

If it occurs at random, I would focus on the extractor.  See the link posted above to my extractor tuning notes.  It could be your extractor spring is "sprung", or you may need to stone down the area behind the hook so it can get a better grip.  If it worked OK in the past, it's most likely to be either wear or dirt.

Also, make SURE your chamber is clean.  Running a used .22 caliber brush through it won't do much of anything.  I use a .25 caliber rifle brush bent at 90 degrees to clean the chamber (see attached picture).

Ok, thanks. I checked the extractor and the extractor and slot were pretty dirty. I tugged on the spring and made it a bit longer (I hadn't checked the force with the trigger gauge).  When I check the force now with the fishing braid and trigger gauge it's the 1.8 lbs which was at the margin of when you mentioned problems begin so that spring must be done. The gaps on the hook look pretty good compared to your guide so no stoning seems to be needed. Pardini in another note said FTE is usually the recoil spring or o rings but these had recently been replaced by the prior owner. I'll get some more in case the extractor spring replacement isn't enough. Someone else said CCI SV is hotter than some other match ammo so the bolt timing may be running too fast (presumably due to recoil spring and buffer inadequacy.)

Also, I see Pardini in 2013 mentioned the back recoil buffer, part 717, but when I look in my pistol 2013 SP I don't see that there is one in the back of the bolt. It looks like just aluminum. Perhaps these are just for the bullseye edition that needs something that also works for the 32 cal or maybe mine is missing?  I'm not clear on that. Another thread mentions the o rings aren't needed if you have that back buffer. Do you know if all SPs should have that part?

"Hi! Usually this problem happens when the recoil spring (part 713) and the back shock absorber (part 717) are getting tired. We recommend the replacement every two years or 7500 - 10000 round. The reason is the too fast closing of the bolt. This is the case with 90% of the pistols that start doing "stove pipe". In few cases the reason is beaten ejector (you can observe the shape and see if there is any "swelling" of the tip); problem with the extractor (part 711) and/or extractor spring (part 712) -you have to replace them every 3-4 years based on the usage; and very rarely when you have worn off chamber (we have only two such cases).
The small parts you can order online at: [ltr]www.pardiniguns.com/store[/ltr]
Here is a diagram with all parts for the SPNew model:
[ltr]http://www.pardiniguns.com/store/images ... iagram.gif[/ltr]
If you have any questions, please do not hesitate to contact us.
Have a great day!"

I'm not sure exactly when Pardini made the change, but sometime between ~ 2008 and 2015, they switched the buffer system from a custom molded green part that fits in the back of the frame to a stack of O-rings in the bolt.  If you dig around, you can find info on substitute O-rings that are much less expensive than what Pardini sells, although the factory appears to have switch to a polyurethane material, which should last longer than the Nitrile O-rings that are easy to find.

Pardinis should shoot CCI standard velocity just fine.  HOWEVER, CCI rounds tend to run near the SAAMI maximum for overall length, and longer rounds can hang up in the magazine.  I've got two cases of CCI that are really long, and won't feed reliably in either Pardini or Benelli magazines.  I did an extensive survey of different ammo, measuring 50 rounds of everything I could find.  Seven lots of CCI all ran longer than the longest of any other ammo I measured, US or foreign.  The SAAMI spec has a huge tolerance range, and most European ammo tends to run closer to the middle of that range.  I have passed this on to the CCI factory, but if they do anything about it, it may be a while before it reaches the stores.