MPX tuners come inside. I’ve got a paperweight

[Nathanb]

I’ve hit my limit with this thing. I’ve got an early gen 1 gun that ran perfectly before it nuked the bolt and carrier and had to go to sig to be repaired. I’ve got the factory 8 inch barrel and a 4.5 that were flawless both suppressed and unsuppressed. 

 

 

Now. It doesn’t run. Either barrel. Suppressed or not. It fires one round and does not fully extract while trying to feed the next round.  I’ve tried swapping gas plugs from the barrel assemblies and still nothing. One has an inleadwetrust open plug and the other is a factory sig. my guess is they put the gen 2 plug in before they sent it back. 

 

Ive tried different ammo.  Same thing.  I’ve tried the inleadwetrust springs for the gen 1 guns. Same thing. I’m at the point where I have no idea what to try next. 

 

Does anyone know the differences in the gen 1 and gen 2 recoil springs?  

 

Is the open plug not right for this? Should it be running a smaller port on the plug?

 I’m at a lost and I’ve got a boatload tied up in this thing and there’s no way I’m sending it back to suck ass sig yet again

[Rolex]

Take apart the extractor, clean,  and then replace spring and the plunger- try that

[Nathanb]

The spring and extractor are all brand new as part of the refurb by sig. I don’t have twenty rounds on it. But I’ll check it again and see. I’ve been looking at gas and it might not even be. 

 

At this point i dont even know what gen bolt and carrier I have ugh

[George16]

Can you post pictures? I just got my MPX PCC last Friday and took it all apart for intensive cleaning and comparison with my gen 2. I took pictures of the bolt, gas plug and measured the gas plug opening too. 

 

Here are some pics:

 

 

extractor. It now has an additional oring. Old one in my gen 2 8” didn’t have the oring. Just the spring and rubber insert.

 

gas plug, no more washers inside and roll pin like the older plugs on the gen 1 and 2 . Port size is .185-.186”

 

Detachable carriage assembly and bolt, old ones are held together by a roll pin

 

Firing pin and spring. Spring is spiral wound type unlike the regular spring on the old ones

 

 

 

[George16]

Here’s the gas plug from my 8” gen 2

 

 

[Smithcity]

28 minutes ago, George16 said:

Can you post pictures? I just got my MPX PCC last Friday and took it all apart for intensive cleaning and comparison with my gen 2. I took pictures of the bolt, gas plug and measured the gas plug opening too. 

 

Here are some pics:

 

 

extractor. It now has an additional oring. Old one in my gen 2 8” didn’t have the oring. Just the spring and rubber insert.

 

gas plug, no more washers inside and roll pin like the older plugs on the gen 1 and 2 . Port size is .185-.186”

 

Detachable carriage assembly and bolt, old ones are held together by a roll pin

 

Firing pin and spring. Spring is spiral wound type unlike the regular spring on the old ones

 

 

 

Lol, i have two gen 2s purchased a year apart, they also had internal dofferences. Not sure how sig can call these guns a gen 2 with the number of changes they have made. Seems they are really at gen 7 or 8 at this point.

 

Neither of mine run reliably. After getting regularly screwed by the mpx in competition,  got a JP so i could finish a match without malfunctions. 

 

Any guesses  on why sig keeps making all these changes? Why make these changes if the gun runs reliably? Oh thats right, because it doesnt, so they continue to use their customer base as beta testers years after releasing the product.

Edited June 2, 2019 by Smithcity

[George16]

10 minutes ago, Smithcity said:

Lol, i have two gen 2s purchased a year apart, they also had internal dofferences. Not sure how sig can call these guns a gen 2 with the number of changes they have made. Seems they are really at gen 7 or 8 at this point.

 

Neither of mine run reliably. After getting regularly screwed by the mpx in competition,  got a JP so i could finish a match without malfunctions. 

 

Any guesses  on why sig keeps making all these changes? Why make these changes if the gun runs reliably? Oh thats right, because it doesnt, so they continue to use their customer base as beta testers years after releasing the product.

Lol. Mine has worked well until that roll pin backed out allowing the gas plug to unthread itself. I had 7149 rounds on that 8” until it malfunctioned. If the roll pin didn’t back out, it would have never malfunction. I keep it simple so as not to complicate things. They’re simple designs only complicated by shooters pursuit of flatness and no visible dot movement .

 

Ill find out how my new one will run after awhile. I’ll dissect it and will find a solution if it doesn’t. We shall see.

 

Edit - send me one of your gen 2s so I can play and troubleshoot it.

Edited June 2, 2019 by George16

[Nathanb]

I’ll get some pictures up shortly. Mine ran great until the carrier and bolt broke. It was a favorite. Now it just sucks. 

[Rolex]

2 hours ago, George16 said:

Lol. Mine has worked well until that roll pin backed out allowing the gas plug to unthread itself. I had 7149 rounds on that 8” until it malfunctioned. If the roll pin didn’t back out, it would have never malfunction. I keep it simple so as not to complicate things. They’re simple designs only complicated by shooters pursuit of flatness and no visible dot movement .

 

Ill find out how my new one will run after awhile. I’ll dissect it and will find a solution if it doesn’t. We shall see.

 

Edit - send me one of your gen 2s so I can play and troubleshoot it.

SOOO the new extractor spring is re by the looks of it!!

[George16]

6 minutes ago, Rolex said:

SOOO the new extractor spring is re by the looks of it!!

Yup. It’s thicker than the gen 2 extractor spring too. I think they added the oring since it has now an open gas plug. Just my guess.

 

by the way, are you coming to shoot at fernandina beach this coming Saturday?

 

 

 

Edited June 2, 2019 by George16

[Rolex]

No, i am down to only 2 matches a month now.

Just dont want to travel anymore.