Strange SX3 jam

[BoyGlock]

Its a 3" gun. Happens in the middle of fast shooting like in a bunch of close targets in 3 gun. The bolt is not quite close but almost. Trigger actuated but wont fire, leaving a very light mark of the firing pin on the primer. Bolt cannot be moved forward or rearward no matter how hard the bolt handle is pulled or pushed without breaking it. A bit later, the bolt can be retracted again although with some effort. After its cleared the gun would shoot reliably again. Until the next iteration. The first few times it happened I though the shells were expanded preventing the bolt to move. But upon detailed inspection, ammo were in specs. When fed again they fire and cycle without any problem. Happens about 1 in 75-100 rounds. I think something is mechanically preventing the bolt to move. Has anybody experienced this, and if so what causes and cures this jam? Thanks 

[Dan Sierpina]

This may sound strange but, try a different brand of ammo. Rio does essentially the same thing on my Super Nova. Different brand, no problems.

[BoyGlock]

On 2/4/2017 at 9:04 PM, Dan Sierpina said:

This may sound strange but, try a different brand of ammo. Rio does essentially the same thing on my Super Nova. Different brand, no problems.

I'll try though I dont have much option on other ammo brands in quantity except armscor in my side of pond.  

 

Thanks. 

[Dan Sierpina]

Where are you located?

 

[BoyGlock]

5 hours ago, Dan Sierpina said:

Where are you located?

 

Ph. 

And Win warranty service is non existent here. 

[bushmeat]

1 in 75 or 100 is about par with Rios, Fed bulk or Rem Gun Club. Not the gun.

[BoyGlock]

21 hours ago, bushmeat said:

1 in 75 or 100 is about par with Rios, Fed bulk or Rem Gun Club. Not the gun.

I hope its not the gun, too. 

But everytime it happens I retrieve the shells, mic them, found them in spec, fed and shot them again without any problem. 

Last range session I run the gun well lubed in the bolt area. No problem so far. But it was a lot less than a hundred. 

I usually run it (as all my guns) sparingly oiled only on known contact/sliding surfaces only. 

[Dan Sierpina]

I think it has to do with the plastic, not the length, diameter and head of the shell.

 

[BoyGlock]

Can you elaborate on the plastic issue pls?

[Dan Sierpina]

Something do with the hardness of the plastic. 

[BoyGlock]

I will be aware of that, thanks

[general_cluster]

Against better judgement, I just sold an SX3 that I was using for 3 gun.  I already miss it.

 

So when this happens can you wiggle the bolt at all?  If you cannot, them it is, as you suspect, a mechanical issue and not one with the ammunition. If you can move the bolt a tiny bit, then it may be related to the shell binding.  

 

if it is mechanical, intermittent, and binds in both directions, that suggest to me that the bolt is binding vertically in the carrier.  That could be happening where the lug engages the barrel, at the sloped area that pushed the bolt up, or at the sides of the bolt where it contacts the carrier.  I'd check for abnormally tight fit, debris, and damage in those areas.  It seems like it might be happening when the gun is hot and resolves when cool, which further suggests a tight fit that binds with thermal expansion.

 

if it is not mechanical, but rather with a shell, make sure that the extractor cut in the chamber isn't raising a bur on the plastic hull of The shell

and causing it to bind.  I broke that edge over on mine with a stone to prevent hang ups.

 

any pictures might help.  Hope you get it sorted out!

 

[BoyGlock]

On 2/10/2017 at 6:06 PM, general_cluster said:

Against better judgement, I just sold an SX3 that I was using for 3 gun.  I already miss it.

 

So when this happens can you wiggle the bolt at all?  If you cannot, them it is, as you suspect, a mechanical issue and not one with the ammunition. If you can move the bolt a tiny bit, then it may be related to the shell binding.  

 

if it is mechanical, intermittent, and binds in both directions, that suggest to me that the bolt is binding vertically in the carrier.  That could be happening where the lug engages the barrel, at the sloped area that pushed the bolt up, or at the sides of the bolt where it contacts the carrier.  I'd check for abnormally tight fit, debris, and damage in those areas.  It seems like it might be happening when the gun is hot and resolves when cool, which further suggests a tight fit that binds with thermal expansion.

 

if it is not mechanical, but rather with a shell, make sure that the extractor cut in the chamber isn't raising a bur on the plastic hull of The shell

and causing it to bind.  I broke that edge over on mine with a stone to prevent hang ups.

 

any pictures might help.  Hope you get it sorted out!

 

 

Think you described it more accurately than I did. The bolt wont move a bit forward or aft and it happens when gun is hot. After cooling down about a few seconds later I could move the bolt and clear the jam and shoot again as if nothing happened. I stripped the bolt more than a few times to look for binding mark(s). Saw nothing unusual. My latest and last remedy was lube the bolt, carrier and locking notch in the barrel extension more than my usual minimalist way. I also change my lube into one that stays in place even when hot and lots of mechanical movements. (My previous one, a synthetic auto engine oil, wont do that much as I noticed when cleaning my guns) Seemed to solve the problem. Shot the sx3 for more than a hundred in practice and local 3gn match without any issues so far. Hope its really all ok now as Im gearing for my first real 3gn match next week. 

 

Thanks everyone! Will keep you updated. 

Edited February 19, 2017 by BoyGlock

[BoyGlock]

Just finished 6 stages 3gun and 5 stages shotgun matches. My SX3 ran without any hiccup. 

Now, lots of things that need to learn and practice... its now a software issue.