Sig MPX- Light primer strikes

[Erik88]

I just got back from visiting my friend in Fentress County. We shot my MPX for a while until I started getting light primer strikes. I tried Blazer 124 grain and Geco 115. I then loaded them in my Glock and they fired without issue. Eventually I just got a click and didn't even see marks on the primer.

A google search showed quite a few MPX owners saying the tip of their firing pin broke off. I've not had a chance to look yet.

Anything else I should check? Never had this happen with any gun I've owned.

[JunkiCosmonaut]

Did you get any striker/pin drag before this? 

[Erik88]

1 hour ago, JunkiCosmonaut said:

Did you get any striker/pin drag before this? 

No. It's had a few FTF over the years but never this. I've shot that 124 grain Blazer through it without issue in the past.

[JunkiCosmonaut]

3 hours ago, Erik88 said:

No. It's had a few FTF over the years but never this. I've shot that 124 grain Blazer through it without issue in the past.

Its odd for sig to have issues with regular use for sure. Damaged pin seems to be most likely, but even at that I would think the pin wasn't quite right to just break or bend.

[Chucktshoes]

Sigs having firing pin issues isn’t exactly unheard of...

[Erik88]

8 hours ago, Chucktshoes said:

Sigs having firing pin issues isn’t exactly unheard of...

Funny that the most expensive gun I've ever owned hasn't been my most reliable. 

[Chucktshoes]

15 minutes ago, Erik88 said:

Funny that the most expensive gun I've ever owned hasn't been my most reliable. 

1911 guys reading this be like:

[Capbyrd]

I had an AR firing pin tip break off one time.  I contacted the manufacturer of the BCG and they told me that they had a bad batch of pins.   They mailed me a new one and its been fine since.  Pull the bolt apart and check the pin.   If others are already having the same issue, it's a good place to start. 

 

[Darrell]

I have a Winchester MDL 70 rifle that occasionally has light firing pin strikes. In my case, the lube on the firing pin had thickened, causing the pin to move sluggishly. There were light marks on the primers. I used some One Shot (Hornady product, I think) and everything freed right up. But I've had repeat performances.

I would think a striker would be more prone to sluggishness than a FP, but I have no experience with Sig pistols.

[Erik88]

It's hard to tell but I'm thinking the tip might be broken off. What do you guys think? It's very course too. I would expect the metal to be smooth.

 

[Erik88]

I found this picture on sigtalk that shows a broken one up top and the new one below. I'm thinking mine looks closer to the top picture. Anyone else agree?

 

[Chucktshoes]

That tip is sheared off. 

[Garufa]

3 minutes ago, Erik88 said:

It's hard to tell but I'm thinking the tip might be broken off. What do you guys think? It's very course too. I would expect the metal to be smooth.

 

That's busted.  Will SIG send you a new one?

[Erik88]

1 minute ago, Garufa said:

That's busted.  Will SIG send you a new one?

Pretty sad for only 1,500 rounds(likely less). Most guys reported them breaking around the same round count. Calling Sig now. 

[Capbyrd]

6 minutes ago, Erik88 said:

It's hard to tell but I'm thinking the tip might be broken off. What do you guys think? It's very course too. I would expect the metal to be smooth.

 

 

you broke your tip! 

[Erik88]

@MacGyver i know you have an MPX. Do you know if mine is a Gen 1 or 2? I'm getting conflicting info online.

I thought it was a Gen 2 but doesn't have a serial number on that time frame.

 

[MacGyver]

That's a gen 2 rail.  Is your charging handle ambidextrous?  My gen 1 is not.

It's kind of table stakes - but it's not unheard of to get a bad heat treat on a batch of pins.

[Erik88]

21 minutes ago, MacGyver said:

Is your charging handle ambidextrous?

Yes it is. That confirms what I thought. That post with the serial # must have been wrong. Apparently they changed the firing pin at some point and included a spring. I think I'm outside the 5 year warranty so we'll see what they say. 

 

[JunkiCosmonaut]

I knew the p365 had a lot of issues on launch, but striker drag on tiny pistols isn't something entirely abnormal. Im surprised at the shearing.

[Erik88]

Just got off the phone with Sig. The employee seemed surprised to hear about the firing pin. They have completely redesigned the the BCG and firing pin and don't have any spare parts they can send me. The only option is to send back the upper on their dime. Apparently the repair shop has the parts to fix it and send it back. He even said it was an overkill solution to a simple problem. Hopefully the new design is an improvement and the gun will be reliable after this. 

 

 

Edited December 2, 2020 by Erik88

[Chucktshoes]

7 hours ago, Erik88 said:

Just got off the phone with Sig. The employee seemed surprised to hear about the firing pin. They have completely redesigned the the BCG and firing pin and don't have any spare parts they can send me. The only option is to send back the upper on their dime. Apparently the repair shop has the parts to fix it and send it back. He even said it was an overkill solution to a simple problem. Hopefully the new design is an improvement and the gun will be reliable after this. 

 

 

They redesigned the firing pin?

[Erik88]

7 hours ago, Chucktshoes said:

They redesigned the firing pin?

Ha! Shocking I know! That picture I posted above is what the new one looks like apparently. Mine doesn't have that spring. The entire bolt carrier group is different too. I really wish the would just send me the new parts. 

[Erik88]

To Sig's credit, they had my upper on the way back to me within 2 days of receiving it. They didn't send me a new BCG but they did install a new firing pin with a spring.  Hopefully this one lasts a bit longer. 

[DaveTN]

17 hours ago, Erik88 said:

To Sig's credit, they had my upper on the way back to me within 2 days of receiving it. They didn't send me a new BCG but they did install a new firing pin with a spring.  Hopefully this one lasts a bit longer. 

A couple of days turn around during CRB is excellent. Good to see someone’s customer service is doing what they should.