Can p320's fire out of battery?

[dansedgli]

I bought a 2nd hand pre upgrade p320x5 this week. In Australia so no easy voluntary upgrade path.

 

It hasn't been modified apart from an R1 on top.

 

Shot about 300 rounds out of it so far, 200 of those tonight.

 

While I was cleaning up tonight I found these 2 cases.

 

I barrel dropped a hand full afterwards and all was ok, the cases don't seem terribly supported though.

 

I've not seen anything like this before. The rounds make about 132pf out of my shadow 2.

 

This isn't safe right?

 

Any ideas what has happened? I load on auto 1050, these were in a batch of about 7000 rounds. Half of which have been fine in my shadow 2.

 

 

 

Edited February 22, 2019 by dansedgli

[dansedgli]

There's a whole bunch of problem cases in my empties.  

[Hi-Power Jack]

Have you run The Plunk Test on those rounds, in your new P320 ?

 

Looks like the rounds have not bottomed out (Plunked) in the chamber,

and then still managed to fire (don't know how they would fully close

the slide and fire) ?

 

I've never seen anything like that - but wouldn't fire any more of those

rounds in that gun until you determine what the problem is.

 

 

[Sarge]

2 hours ago, dansedgli said:

I bought a 2nd hand pre upgrade p320x5 this week. In Australia so no easy voluntary upgrade path.

 

It hasn't been modified apart from an R1 on top.

 

Shot about 300 rounds out of it so far, 200 of those tonight.

 

While I was cleaning up tonight I found these 2 cases.

 

I barrel dropped a hand full afterwards and all was ok, the cases don't seem terribly supported though.

 

I've not seen anything like this before. The rounds make about 132pf out of my shadow 2.

 

This isn't safe right?

 

Any ideas what has happened? I load on auto 1050, these were in a batch of about 7000 rounds. Half of which have been fine in my shadow 2.

 

 

 

Those simply are not fitting all the the way in the chamber. I’m flabbergasted those fired though. Where is the primer strike? Is it off center?

[titandriver]

[dansedgli]

6 hours ago, Sarge said:

Those simply are not fitting all the the way in the chamber. I’m flabbergasted those fired though. Where is the primer strike? Is it off center?

 

Plunk test seems ok but i didn't test until afterwards. The cases can be pushed and turned, i dont think it's a length issue. 

 

The case head is flush with the barrel hood like with a 1911. Should it not be that way? 

 

Primer strike was centered. I guess that means the barrel was in lock up? 

 

 

[dansedgli]

Did you get a solution from sig titandriver?

[Sarge]

1 hour ago, dansedgli said:

 

Plunk test seems ok but i didn't test until afterwards. The cases can be pushed and turned, i dont think it's a length issue. 

 

The case head is flush with the barrel hood like with a 1911. Should it not be that way? 

 

Primer strike was centered. I guess that means the barrel was in lock up? 

 

 

Pushed and turned? They should fall all the way ay in and fall out when you invert barrel. They should spin freely without any pushing.

[dansedgli]

Yeah they plunk in and drop out. You push and turn them to make sure the case is what is stopping it rather than the projectile.

 

If too long they wont turn as the projectile is jams in the rifling. 

[Hi-Power Jack]

13 hours ago, dansedgli said:

 they plunk in and drop out. You push and turn them 

 

The confusion is over the term "PUSH" ...

 

When I run The Plunk Test, the cartridge drops all the way in - you cannot PUSH it in any further.

 

If you can PUSH it in further, the cartridge has failed The Plunk Test.

 

 

[dansedgli]

Pretty tricky stuff. 

 

Are all x5 chambers this unsupported looking? That round appears to plunk just fine. 

 

 

 

 

[9146gt]

4 hours ago, Hi-Power Jack said:

 

The confusion is over the term "PUSH" ...

 

When I run The Plunk Test, the cartridge drops all the way in - you cannot PUSH it in any further.

 

If you can PUSH it in further, the cartridge has failed The Plunk Test.

 

 

With some bullet profiles like HAP I have found it best to twist after the Plunk to assure that you are not touching the rifling.

 This is a must in most PSA 9mm PCC chambers.

Tom

[Hi-Power Jack]

From your photos, it seems that an awful lot of case is not

supported by barrel, and in exactly the place that the cases

are ballooned.

 

Surprised others are not having a similar problem with the P320 

[titandriver]

On 2/22/2019 at 1:36 PM, dansedgli said:

Did you get a solution from sig titandriver?

Negative.

[dansedgli]

4 minutes ago, titandriver said:

Negative.

 

sorry to hear. 

[titandriver]

2 hours ago, dansedgli said:

 

sorry to hear. 

To be fair, I never contacted Sig. I had a 'smith lengthen the chamber a thousandth and have had no problems with that barrel since. I have two other 320's that never exhibited the problem with bulging brass so left those alone. 

[titandriver]

Oh yeah - my barrels were all marked differently, one had no markings on the rearmost part of the barrel, one has "Sig" marked on it, and one has the letter "C" on it.

[titandriver]

'Nother oh yeah - the brass that bulged was all PMC.

[dansedgli]

Thanks mate.

 

Hopefully I can get it fixed through the supplier. It's a shame, Ive just ordered a trigger kit and bunch of other stuff for it.

 

 

[BallisticianX]

I know this post is a few months old but just stumbled on it researching my similar experience. I have a P320RX of early 2019 manufacture (not the X5 series). FIrst off the pics are of a correctly seated round. The head should be flush to a few thousand lower than the hood. While at a match this past Saturday I had a case failure that bulged identical to yours that also ruptured the case right in the belly of the extractor groove about 3/4 of the way around. Was surprised it ruptured right in the meat of the web as usually a "weak case" breaks open where the case wall meets the web area. Im running a 135 gr. bullet with 3.8gr of A#2 of which is not a stout load.  I can also confirm it was not and overcharge as I visually inspect the powder in each case when I manually set the bullet for seating. It just snapped when fired and between the sound and the slide barely moving I thought it was a squib at first. But when I cleared the gun I saw the deformed case freely drop out of the chamber despite my extractor being MIA. No heavy black residue or blown out mag etc, just a missing extractor.

I long suspected the healthy clearance at the chamber on this gun was an issue as my spent cases always slightly bloated a bit at the web and this is just more confirmation. My opinion is my situation was compounded by a piece of brass that may have been weakened by previous firings. The unsupported nature of this barrel wont tolerate much in the way of any weakening from cases that have been reloaded even only a few times. Ive also noticed loading to longer COL's that will still pass the plunk test will exhibit more case bulging than if loaded shorter. Seems like the bullet needs a good amount of bullet jump to buffer pressure to make up for the lack of chamber support. Kinda like a 5.56 nato chamber incorporates bullet jump to prevent pressure. I like the P320 but this chamber design and what I've experienced raises doubts for me. I'm looking into an after market barrel in hopes it may have more support. We shall see!  

[Aircooled6racer]

Hello: One thing to check also is the overall length of the case. I know if I try to use S&B 9mm brass in my open pistol I have problems with bulged cases and sometime extraction problems since the brass is shorter than other brass. I am not sure what recoil springs you guys are using since using one that is a little too light will cause problems also. Thanks, Eric

[jcc7x7]

Gus:

Going by memory, so take it for what it's worth! Lol

Dansedgli's gun was sold to another shooter in Australia and seems to be working fine for the new owner.

Again by memory think the new owner changed to a slower powder and MAYBE a heavier spring to solve the issue.

Again this is all by memory, hopefully they will chime in.

 

I'm using 12-14lbs springs in 4 different x5s and one RX.  I've had a few empty gun starts that didn't get the slide in battery and wouldn't fire or had

a light strike.  Every time I could easily trace it to trying to go with too light of a recoil spring. Or riding the slide home!

BUT fortunately I've never had a case do what is shown above in the photo's.  Mine just didn't go bang or wouldn't even allow the striker to fire.

 

Might look at the powder speed vs bullet weight etc.

 

FWIW -  I'm using 3.0grs of e3 with Bayou 145RN at 1.150

or 125 Bayous with 4.16 WST at 1.150 (gone as short at 1.125)

Also an assortment of 124/5 FMJ with the WST load a 1.165

Brass is whatever is in the brass barrel at the club with the exception of stepped brass.

Everything else works fine S&B, Maxtech, Extreme, Perfecta, Aquilla, of course any of the good US made stuff.

Mine have been very easy keepers with loads and brass.

 

Good fortune with solving the problem

[dansedgli]

I had 2 x5's. 1 early one mentioned here and one made at the end of 2018. Both bulged cases with the combination of powder and cases I was using.

 

If I used a slower powder OR different cases they didn't bulge. In the end I was running a 10lb spring in the newer gun, it couldn't fire out of battery with the upgraded drop safety work and ran well apart from the odd case bulge (it bulged with the factory springs too).  A tiny bit of slide movement would disengage the trigger. The earlier gun could fire with the slide moved a lot futher back but not entirely out of lockup. 

 

I sold both x5's and am now enjoying the pleasures of full case support in 2011's again. 

 

edit: the cases that bulged or blew out were PPU, Tulammo and the very odd CBC. PPU bulged every time, even genuine once fired brass, Tulammo blew out and the odd CBC one would have been a super old case. Quite entertaining shooting a mag full of PPU and watching peoples reactions as they pick up your brass.  

 

 

 

 

Edited October 8, 2019 by dansedgli

[terrydoc]

3 hours ago, jcc7x7 said:

Gus:

Going by memory, so take it for what it's worth! Lol

Dansedgli's gun was sold to another shooter in Australia and seems to be working fine for the new owner.

Again by memory think the new owner changed to a slower powder and MAYBE a heavier spring to solve the issue.

Again this is all by memory, hopefully they will chime in.

 

I'm using 12-14lbs springs in 4 different x5s and one RX.  I've had a few empty gun starts that didn't get the slide in battery and wouldn't fire or had

a light strike.  Every time I could easily trace it to trying to go with too light of a recoil spring. Or riding the slide home!

BUT fortunately I've never had a case do what is shown above in the photo's.  Mine just didn't go bang or wouldn't even allow the striker to fire.

 

Might look at the powder speed vs bullet weight etc.

 

FWIW -  I'm using 3.0grs of e3 with Bayou 145RN at 1.150

or 125 Bayous with 4.16 WST at 1.150 (gone as short at 1.125)

Also an assortment of 124/5 FMJ with the WST load a 1.165

Brass is whatever is in the brass barrel at the club with the exception of stepped brass.

Everything else works fine S&B, Maxtech, Extreme, Perfecta, Aquilla, of course any of the good US made stuff.

Mine have been very easy keepers with loads and brass.

 

Good fortune with solving the problem

I'm the new owner and at this time I'm using the Syntech 150gn exclusively in it, however I am starting to experiment with 147 gn reloads. 

[BallisticianX]

On 10/8/2019 at 7:05 PM, dansedgli said:

I had 2 x5's. 1 early one mentioned here and one made at the end of 2018. Both bulged cases with the combination of powder and cases I was using.

 

If I used a slower powder OR different cases they didn't bulge. In the end I was running a 10lb spring in the newer gun, it couldn't fire out of battery with the upgraded drop safety work and ran well apart from the odd case bulge (it bulged with the factory springs too).  A tiny bit of slide movement would disengage the trigger. The earlier gun could fire with the slide moved a lot futher back but not entirely out of lockup. 

 

I sold both x5's and am now enjoying the pleasures of full case support in 2011's again. 

 

edit: the cases that bulged or blew out were PPU, Tulammo and the very odd CBC. PPU bulged every time, even genuine once fired brass, Tulammo blew out and the odd CBC one would have been a super old case. Quite entertaining shooting a mag full of PPU and watching peoples reactions as they pick up your brass.  

 

 

 

 

The case that had a rupture failure for me was marked "P-A RH". I researched it to a company called Precision Ammunition. God knows where the brass was made or what was loaded in it and how many times it was fired before it made its way into my brass bin. Though my cases have never bulged as extreme or as regular as the OP, Ive taken steps to prevent any future issues. I measured and adjusted my COL for .030" clearance from bullet driving band to lands, moved from a 13lb to a 14lb recoil spring, and completely sorted out brass with any off brand headstamp. The case support in these P320 barrels is a point of paranoia for me. The OP's barrel pics show way to much 45 degree chamfer for my liking. My particular barrel does not have near that much but instead it funnels inward, like they used a revolver forcing cone cutter on the 1st 3/16" of the chamber. Both approaches leave too much area for cases to bloat into in my opinion.