FTExtract on MPX

[George16]

I was doing great during last Saturday’s local match until I got to the last stage. My 8” gen 2 MPX started failing to extract multiple times and I just stopped shooting with 3-4 more targets left.

 

I didn’t tear apart my MPX until Monday evening and this is what I found:

 

 

The roll pin that keeps the gas plug stationary worked itself out and let the plug unthread itself. In doing so, the MPX was undergassed hence the failure to extract. I called sig customer service yesterday asking for extra roll pins but the guy said they can’t send any but nonetheless, he offered to email me an RMA to send my MPX to Sig. I told him my MPX is an SBR so he said I can just send the upper which I did after removing all the aftermarket parts (I CGW cf hand guard, red dots, raptor CH etc). I asked him if Sig can just replace the gas valve itself since I need my MPX as soon as possible. We’ll see.

 

I initially thought it was the extractor since my MPX has 7149 rounds through it since buying it November of last year but the extractor is still intact. Nevertheless, I told the rep to have them replace the extractor spring and rubber insert too. Now I know that there are 20 little washers inside that gas valve. 

 

 

 

 

 

 

 

 

Edited May 29, 2019 by George16

[Nathanb]

I wish you better luck than I had when I sent mine in. I’m still trying to get it to run

[George16]

9 minutes ago, Nathanb said:

I wish you better luck than I had when I sent mine in. I’m still trying to get it to run

Thanks.

 

Its been running flawlessly since buying it. This is the only malfunction I ever had. At least I know the cause instead of just troubleshooting blindly. I’m going to order the MPX PCC direct from Sig so I can get my discount.

 

I hope you can get yours sorted out sooner instead of later.

[jlo86cj]

All they are going to do is install an open gas plug...they phased out the old spring type. If you haven't shipped it out yet, don't. I'll send you an open plug to keep you running.

 

Jimmy

Edited May 29, 2019 by jlo86cj

[George16]

42 minutes ago, jlo86cj said:

All they are going to do is install an open gas plug...they phased out the old spring type. If you haven't shipped it out yet, don't. I'll send you an open plug to keep you running.

 

Jimmy

Jimmy,

I just ship it out yesterday afternoon. Damn it! Actually, when I removed the threaded plug, I didn’t see any spring inside. All I saw were 20 pieces of washers like these.

 

So, is this a newer plug/gas valve or still the older style? 

 

Thanks for the offer though. I just ordered a new MPX PCC an hour or so ago. I’ll be picking it up from the ffl on Friday. I also ordered a spare extractor from ILWT, BCM spring kit (because I remember you telling me that before at Sapsa). 

 

Lito

[jlo86cj]

Those washers are what I was referring to as springs. The assembly acts like a pressure relief, but usually clogged quick and then it was pretty much just like an open plug. I had to send my older gun in for a broken bolt carrier, so I put the original barrel assembly and this style gas plug back in it. They sent it back to me with an open plug. 

 

The new PCC model has a heavier (red) extractor spring that should treat you right for at least 5k rounds.  

[George16]

Oh I see. Crap! I wish I would have known this prior to sending it out. I didn’t tear it apart until yesterday since the match at Ancient City last Saturday.

 

Ill give them a call today and let them know that I want to keep the original plug and just have them replace the roll pin then. Hopefully that will be the case. Thank you very much for your help.

[jlo86cj]

I would just go with the open plug...I doubt you'll notice a difference. If they happen to reassemble that one and send it back, I would still try an open. It is one piece and wont fail on you at the worst time;)

[George16]

That’s true,. We’ll see how sig handles this crap. 

 

Have vel you heard about this pin coming out and causing problems before?

[jlo86cj]

Yeah, it has been an issue for others.

 

[SergioSF]

4 hours ago, George16 said:

That’s true,. We’ll see how sig handles this crap. 

 

Have vel you heard about this pin coming out and causing problems before?

 

Happened to mine too. Heed jlo86cj's advice and pick up a new plug from In Lead We Trust. (pick up a few so your dirty one can soak while you plug in a fresh one. While you're shopping there, might as well pick up a couple of the pistons too. Get a couple for the same reason).

 

I'll bet someone will chime in and say you might as well pick up the whole spares kit, which is a really good idea.

Edited May 29, 2019 by SergioSF

[Rolex]

48 minutes ago, SergioSF said:

 

Happened to mine too. Heed jlo86cj's advice and pick up a new plug from In Lead We Trust. (pick up a few so your dirty one can soak while you plug in a fresh one. While you're shopping there, might as well pick up a couple of the pistons too. Get a couple for the same reason).

 

I'll bet someone will chime in and say you might as well pick up the whole spares kit, which is a really good idea.

OK I will- George- like  I said- get the kit from ILWT- Rick

[George16]

Rick, I ordered the kit last night and a few hours ago, I ordered a new MPX PCC  

[egd5]

Sorry about your troubles, hope you get it worked out. I almost ordered a new gen 3 mpx too, but ended up going with jp. Hope I made the right decision. Those gen 3s look awfully nice.

How on earth do you keep up so closely with your round count, 7149???   I can't tell you within 5000 how many I've got through my pcc,  but I've had it 3+ years.

[Rolex]

11 hours ago, egd5 said:

Sorry about your troubles, hope you get it worked out. I almost ordered a new gen 3 mpx too, but ended up going with jp. Hope I made the right decision. Those gen 3s look awfully nice.

How on earth do you keep up so closely with your round count, 7149???   I can't tell you within 5000 how many I've got through my pcc,  but I've had it 3+ years.

Geroge16- is how we say- anal- 

[George16]

12 hours ago, egd5 said:

Sorry about your troubles, hope you get it worked out. I almost ordered a new gen 3 mpx too, but ended up going with jp. Hope I made the right decision. Those gen 3s look awfully nice.

How on earth do you keep up so closely with your round count, 7149???   I can't tell you within 5000 how many I've got through my pcc,  but I've had it 3+ years.

All my guns have their own excel document which contains the number of rounds shot on any given day I went to the range. It also has the load for those particular rounds, type of bullet and powder, what type of cleaning that’s done, parts replaced, serial number,  matches attended and how I performed. I always take with me a set number of rounds to the range and plug those in when once I got home. If I didn’t use it all, I count what’s left and subtract that from the total number I took with me. If I ever round out and buy more from the club house, I write the number down in my iphones notes.

 

I used to work with turbine engines before I retired. Part of the inspection and maintenance was to keep track of the hours each turbine engine has ran since its last cleaning and maintenance. Each part has to be replaced before they reach their hourly limits. It was one of my job to keep the MGTESR (Marine Gas Turbine Equipment Service record) up to date which includes tracking run hours for each component so it can be replaced to prevent a catastrophic incident. This is also a legal log which can be used during an investigation if something bad happens so keeping it up to date is critical.

[egd5]

Ookaay!!. I guess old habits are hard to break. Whew, I got tired just reading that though. You certainly have more endurance than me. Or whatever the right word is.

[George16]

1 hour ago, egd5 said:

Ookaay!!. I guess old habits are hard to break. Whew, I got tired just reading that though. You certainly have more endurance than me. Or whatever the right word is.

That’s what happens if you also have too much time in your hands after retiring lol  

[Agrippa]

You will love the PCC, 2000 rounds through mine and I can't get enough 

[George16]

On 5/30/2019 at 7:52 PM, Agrippa said:

You will love the PCC, 2000 rounds through mine and I can't get enough 

I do hope so. I was able to optest it yesterday and so far, so good. I’m hoping it’ll perform well on this coming Saturday’s local match. I do plan on using my gen 2 lower since I have the Hiperfire eclipse trigger in it. I don’t like the Timney trigger that came with the Gen 3 after I had been shooting with the eclipse.

 

I also took it apart last weekend for a complete tear down, cleaning and measurements of important parts for comparison with the same parts in the gen 2. Here’s what I got:

 

MPX gen 3 recoil pad

.520” thick

.790” diameter

Conical shaped

Black

 

Gen 2 recoil pad 

.526” thick

.788” diameter

Circular shaped

 

Gen 2 Taccom recoil wave spring 

.484” without wave spring

.613” with wave spring (1 coil removed)

.936” diameter

 

Gen 2 stock firing pin

2.675” (part # 1810916-R)

 

Gen 3 firing pin

2.678” long

 

Gen 3 firing pin spring (braided)

.682” long

.241” diameter

 

Firing pin spring (braided)

.682” long

.241” diameter

 

Firing pin spring (non-braided)

.584” long

.250” diameter

 

 

So far I’m satisfied with it but it’s too early to tell if it’s going to perform flawlessly. It did ran my reloads without any problems so that’s a huge plus. I used 100 factory federal 115 Gr ammo for the initial break in and after that, all my reloads (RN plated for practice and PD JHP for Competition) using 4.0 Gr of Sport Pistol @ 1.125-1.128” OAL.

[jlo86cj]

Make sure to put the black bumper in the old lower if your using the new bolt carrier.

[Nathanb]

1 hour ago, jlo86cj said:

Make sure to put the black bumper in the old lower if your using the new bolt carrier.

Where did you find the black bumper and how can you tell the difference between carriers

[jlo86cj]

The black bumper comes in the new PCC model. It is tapered to work with the newer bolt carrier in it.

[George16]

2 hours ago, jlo86cj said:

Make sure to put the black bumper in the old lower if your using the new bolt carrier.

Yup. The taper allows it to slide into the end of the bolt carrier whereas the old recoil pad just butts against the outer portion of the bcg. 

 

Thanks Jimmy.

 

edit

by the way, I got a call from sig yesterday telling me that they installed the new gas plug and extractor in my 8” upper. It’ll be arriving through fedex tomorrow and I’m going back to the range on Thursday to optest it. I’m hoping everything will be okay. I asked them if they can send back the old plug and they said no. Bastards lol

 

 

 

 

 

 

Edited June 4, 2019 by George16

[2011BLDR]

2 hours ago, jlo86cj said:

Make sure to put the black bumper in the old lower if your using the new bolt carrier.

My new bolt carrier ( PCC Compitition)  Sig sold me for my oldest gun with 30K + on it,  runs fine against the old buffer set up