SIG MPX failure to eject

[George16]

6 minutes ago, Sfisch0311 said:

Fair enough, haha. I'm just going off of what I have heard. I do know that you don't want a low PF load in it at least. You want something that is really going to work that gun. I'm getting a buddies MPX this week that has had all sorts of issues and I am working up a reliable load for it with that HS-6. Can you provide a link to that thread? 

 

Here’s the thread I started.

 

FTextract MPX 8” gen 2

 

edit 

the gen 3 ran flawlessly too with my gen 2 lower. The huge difference is the recoil pad on the gen 3 is conical which allows it to go into the bolt carrier whereas the gen 2 orange recoil pad or Taccom wave spring I’m using are not conical. It literally is bigger in diameter too.

 

Here are the measurements comparing the gen 2 and PCC model (gen 3)

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

 

 

 

 

Edited June 4, 2019 by George16

[George16]

17 minutes ago, GregJ said:

 

That is exactly my CO load, under 124gr Zeros.  They also run great in my Gen2 MPX, about 140pf, IIRC.  

Yup. Around 140pf.

 

Try using 4.0 Gr of Sport Pistol with the same OAL. It’s a lot cleaner compared to the Winchester 231. This is the main reason I switched to Sport Pistol.

 

I also shoot the same load on my Shadow 2 and X5.

[George16]

19 minutes ago, GregJ said:

 

That is exactly my CO load, under 124gr Zeros.  They also run great in my Gen2 MPX, about 140pf, IIRC.  

double tap 

Edited June 4, 2019 by George16

[zdog]

There is one other change that Sig made to my gen 2 when it was in the the faulure to eject problem.  When it came home it had the red heavy duty extractor spring and they also put an O’Ring around the extractor spring.  That really tightened things up.  And for what its worth when my new competition model showed up it had the same red extractor spring with an O’Ring on it as original equipment.

Edited June 4, 2019 by zdog

[GregJ]

15 minutes ago, George16 said:

Try using 4.0 Gr of Sport Pistol with the same OAL. It’s a lot cleaner compared to the Winchester 231. This is the main reason I switched to Sport Pistol.

 

Will do.  tks. 

[Sfisch0311]

1 minute ago, zdog said:

There is one other change that Sig made to my gen 2 when it was in the the faulure to eject problem.  When it came home it had the red heavy duty extractor spring and they also put an O’Ring around the extractor spring.  That really tightened things up.

That was one thing that I had heard people did or Sig did to help fix the issue. 

[George16]

Just now, zdog said:

There is one other change that Sig made to my gen 2 when it was in the the faulure to eject problem.  When it came home it had the red heavy duty extractor spring and they also put an O’Ring around the extractor spring.  That really tightened things up.

Yup. It matches the same part they’re now using on the gen 3.

 

ill be receiving my 8” gen 2 from sig tomorrow and talking to the rep yesterday morning on my way to the range, he said that they installed the new open gas plug and new extractor. 

 

Itll be be my backup now until both will have the same round count.

[zdog]

1 minute ago, George16 said:

Yup. It matches the same part they’re now using on the gen 3.

 

ill be receiving my 8” gen 2 from sig tomorrow and talking to the rep yesterday morning on my way to the range, he said that they installed the new open gas plug and new extractor. 

 

Itll be be my backup now until both will have the same round count.

 

What is the Gen 3?

[George16]

8 minutes ago, zdog said:

 

What is the Gen 3?

It’s the MPX PCC model which majority of people call “gen 3” but really isn’t.

 

I think it’s the best way to differentiate it from the previous models.

[zdog]

16 minutes ago, George16 said:

It’s the MPX PCC model which majority of people call “gen 3” but really isn’t.

 

I think it’s the best way to differentiate it from the previous models.

 

I guess its easier to write gen 3 than gen 2 competition model.

[George16]

3 minutes ago, zdog said:

 

I guess its easier to write gen 3 than gen 2 competition model.

You’re absolutely right.

[mstamper]

On 6/4/2019 at 11:44 AM, zdog said:

There is one other change that Sig made to my gen 2 when it was in the the faulure to eject problem.  When it came home it had the red heavy duty extractor spring and they also put an O’Ring around the extractor spring.  That really tightened things up.  And for what its worth when my new competition model showed up it had the same red extractor spring with an O’Ring on it as original equipment.

could you take some measurements of that o-ring? I have had a few failure to eject cases and I would like to try the o-ring to see if that helps.

Not sure where I would buy that small an o-ring but at least having the measurements would help start me in the right direction.

 

I wonder if SIG would sell them? hmmmm

[George16]

 

Here are the measurements:

 

5/64” - thickness

1/8” - I.D.

1/4” - O.D.

 

I also took measurements of the BCM extractor spring upgrade kit I have and the o-ring has pretty much the same dimensions as the sig extractor o-ring.  Now I know I can use the BCM oring for my MPX.

 

However, the BCM spring is way taller and stiffer compared to the stock sig extractor spring.

 

Hope this helps.

 

[zdog]

This is what comes on the gen 2 competition model MPX.....

 

 

Edited June 6, 2019 by zdog
Pic

[zdog]

This is the spring.....

 

 

[mstamper]

5 hours ago, zdog said:

This is the spring.....

 

 

where did you order these parts from?

[zdog]

Call Sig and get to customer service.  Tell them your having the failure to eject problem.  The might send them for free, if not I think they charged me $5 each which includes very slow shipping.

[mstamper]

3 minutes ago, zdog said:

Call Sig and get to customer service.  Tell them your having the failure to eject problem.  The might send them for free, if not I think they charged me $5 each which includes very slow shipping.

thanks

[Neomet]

1 hour ago, zdog said:

Call Sig and get to customer service.  Tell them your having the failure to eject problem.  The might send them for free, if not I think they charged me $5 each which includes very slow shipping.

 

Sidebar here but yeah, I would swear Sig walks my parts orders to me.  

 

[Sfisch0311]

11 hours ago, zdog said:

Call Sig and get to customer service.  Tell them your having the failure to eject problem.  The might send them for free, if not I think they charged me $5 each which includes very slow shipping.

There's also a set just plain O-Rings on Amazon that I think will fit it too. I will be testing them out over the weekend, and I can let you all know. And they are only $2.50 for the pack of them. Not to mention I got them in a day with Prime lol.

 

https://www.amazon.com/gp/product/B000KKTVAA/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Edited June 7, 2019 by Sfisch0311

[zdog]

Being basically a tightwad.....I do not share your effort to save a couple of bucks on a small but critical item.  As much time and effort and  money as I spend playing this silly game I want the real deal even though the after market part may work as well, I am not willing to take the chance.  JMHO

[SergioSF]

Or, just buy BCM Extra Power springs, which also come with the right o-ring. 

Buying direct, it's about $19 for a set of three including prompt shipping.

 

Some folks have had luck with running just the extra power spring. Some have been able to squeeze in the spring + O-ring. 

[mstamper]

Or, just buy BCM Extra Power springs, which also come with the right o-ring. 
Buying direct, it's about $19 for a set of three including prompt shipping.
 
Some folks have had luck with running just the extra power spring. Some have been able to squeeze in the spring + O-ring. 

Link to the part please


Sent from my LG-H872 using Tapatalk

[George16]

20 minutes ago, mstamper said:

Link to the part please


Sent from my LG-H872 using Tapatalk
 

Here’s the BCM kit which is identical to the Sig parts.

 

BCM extractor upgrade kit

 

 

 

 

[Sfisch0311]

So to report my results from the load and the spring/detent replacement and addition of the o-ring... The MPX ran like a dream at the match this past Sunday. I did not have a single issue, and the load shot super soft to boot. Will report with any new findings, like how long until spring and o-ring last before replacement.