quote:

Originally posted by Dieseljayy:

Granted since thats the only flaw I have with this gun other than being over gassed when suppressed.

Man I keep seeing and hearing people say that. It's disappointing that Sig got rid of the adjustable gas valve. Every single "auto regulating" gas valve I have seen fails to do so adequately when you put a can on it.

LDD any idea if Sig is going to be bringing back the adjustable gas valve on any variants of either the MPX or MCX?

quote:

Originally posted by Dieseljayy:

quote:

Originally posted by swage:
Has anyone else noticed peening on the top edge of the receiver where the charging handle seems to be hitting? I'm not talking about the normal finish wear. This is actual folding of material on the receiver where the charging handle seems to be making contact. I can email someone pictures to post.

Yeah I have noticed this!

Simple way to solve it is to lock the bolt back then move the handle back forward slowly and lock it. Then close bolt.
Its a clear design flaw of the charging handle. Clearly an afterthought...
I can post pics as well.

The charging handle has vertical play. We are talking +-15 degrees here when you let it go it just bounces against the frame before locking closed.

This is how a charging handle should line up.

This is how gravity and the Sig MpX charging handle line up... Look at that play!



This is what happens to your frame when you release the charging handle.


See how the upper and lower don't line up perfectly. Thats OK. Well kinda. But when your charging handle bounces around like the jokey on riding sea biscuit each time you let it go you get nicks in your upper and a hitler mustache on the back of your receiver.

Granted since thats the only flaw I have with this gun other than being over gassed when suppressed. I'm still super happy with it. Other might want the FYI though about this little issue.

Edit3: round count 7.1k +-300. Charging handle usage<100 times where it was freely released to battery. All other times it was hand guided with locked bolt because this was was mostly from first range session.

Paging LDD...

IMO, this is an issue that should be brought to Sig's attention, as I believe that from a sales and marketing position this is going to create a HUGE problem with this platform getting off the ground in a solid way.

I picked up my MPX-P a week ago yesterday, HAVE NOT FIRED IT YET, and after reading this post yesterday I looked at my MPX and ALREADY SEE SIGNS of this unacceptable wear. To date I have field stripped, separated the upper and lower, cleaned, re-lubed, reassembled and function tested. In addition to that I have MAYBE manipulated and released the bolt 15-20 times.

Here's where this is going to be a problem for Sig...

Once large numbers of these weapons start landing in gun shops, and the gun shop commandos start masterbating the actions, they are going to unknowingly cause damage. Customers won't buy a $1,300 gun that is scared, and more buyers are going to purchase, only to find this damage upon close inspection at home, and they will be PISSED!!! Rightly so, and I don't see the gun shops doing anything to make it right (what can they do - refund???). Finally, the gunshops will become reluctant to stock/sell these guns.

Every "gun guy" out there knows that the Sig MXP platform is raw sex (can we say Kate Moss???) with interchangable barrel lengths/configurations and, ultimately, calibers.

This damage is caused by anodized aluminum on anodized aluminum friction - ultimately the fairly light weight charging handle will wear thin and break, while the back of the receiver developes a gouge in it? Again, I have not even shot my MPX, and I can already see the anodizing wearing through.

Who is going to be excited to spend time and money on filing forms, tax stamps and engraving on something like this???

This message has been edited. Last edited by: JRC,

quote:

Originally posted by jmoyer:
ok guys...I messed up, kind of...

I got my Sig MPX and i love it, but when i got it I ordered the version without the brace.

I see i can order the new brace, but not the knuckle adapter that connects to the picatinny rail. I asked Sig CS and they said it would be available later this summer.

Has anyone seen an alternative source for an adapter? Thanks

everyone!

We have a few of these mounts in stock packages right now but the mounts are very limited at the moment as we make them in our own shop and cant keep up.

1) The MPX never had a manually-adjustable gas piston system, so if it is overgassing (the versions I shot did not have this issue) and they want to do something about it, they're going to have to come up with something new.

2) I did not see the charging handle droop issue with the early pre-production versions that I saw. I'll ask about this when I get the chance. SIG reads these threads so they are no-doubt aware of the issue. I'll see if I can get some commentary.

quote:

Originally posted by LDD:
1) The MPX never had a manually-adjustable gas piston system, so if it is overgassing (the versions I shot did not have this issue) and they want to do something about it, they're going to have to come up with something new.

2) I did not see the charging handle droop issue with the early pre-production versions that I saw. I'll ask about this when I get the chance. SIG reads these threads so they are no-doubt aware of the issue. I'll see if I can get some commentary.

Thank you, LDD. Please keep us appraised of Sig's response to this issue.

quote:

Originally posted by LDD:
1) The MPX never had a manually-adjustable gas piston system, so if it is overgassing (the versions I shot did not have this issue) and they want to do something about it, they're going to have to come up with something new.

2) I did not see the charging handle droop issue with the early pre-production versions that I saw. I'll ask about this when I get the chance. SIG reads these threads so they are no-doubt aware of the issue. I'll see if I can get some commentary.

Sorry, I'm obviously confusing the MCX/MPX. For some reason I thought the MCX changes of replacing the adjustable gas valve had also occurred on the MPX.

quote:

Originally posted by LDD:
1) The MPX never had a manually-adjustable gas piston system, so if it is overgassing (the versions I shot did not have this issue) and they want to do something about it, they're going to have to come up with something new.

2) I did not see the charging handle droop issue with the early pre-production versions that I saw. I'll ask about this when I get the chance. SIG reads these threads so they are no-doubt aware of the issue. I'll see if I can get some commentary.

Interesting that the pre production issues did not have the slop of the charging handle. Wonder what changed?

In another news. The systems only slightly over gasses when unsuppressed. Just the "auto-regulating" seems to make it very over gassed when suppressed.
Additionally: I had my barrel cut down to ~4" and this made a noticeable difference in the over gassed issue and did not change the reliability unsuppressed. Its still over gassed on the 4" suppressed but not as bad as the 8". I am still looking at having a brass/gas deflector that you can buy for an AR retrofitted to the MPX. (The brass always goes 1-2 position the deflector just might help when shooting left handed with that gas).

Lastly: LLD, would you want a detailed strip down set of pictures of all wear parts of the MPX posted when I break the 10k round mark? My next two ranges trips in the next month will put me over that so I just figured I would ask before putting in the effort. Anyone else want to see that?

Great forum and thread, thanks.

1) Fwiw, the $165 Geissele G2S makes a world of difference, it's worth every bit.

2) What kind of cleaning interval do you guys think for the gas piston?

My MPX has maybe 200 rounds through it. I can't say exactly how many times the charging handle has been cycled, but the chips in the upper receiver are much worse than those posted.
I'm a little disappointed, only in the sense that I'm a little over the top about my equipment. Outside of this issue I'm pleased with the platform so far.

quote:

Originally posted by burntorange98:
Great forum and thread, thanks.

1) Fwiw, the $165 Geissele G2S makes a world of difference, it's worth every bit.

2) What kind of cleaning interval do you guys think for the gas piston?

Can anyone explain or post pics how to remove the piston for cleaning?

Owner's manual shows how to disassemble but doesn't mention anything on cleaning interval.

quote:

Originally posted by burntorange98:
Owner's manual shows how to disassemble but doesn't mention anything on cleaning interval.

It mentions it, but no pic on how to do it. Can someone post detailed pics on how to disassemble and tool used. Thank you.

quote:

Originally posted by swage:
My MPX has maybe 200 rounds through it. I can't say exactly how many times the charging handle has been cycled, but the chips in the upper receiver are much worse than those posted.
I'm a little disappointed, only in the sense that I'm a little over the top about my equipment. Outside of this issue I'm pleased with the platform so far.

So a piece of velcro loop in that spot won't help much? I hope Sig sees the is and is working on it.

quote:

Originally posted by JRC:

quote:

Originally posted by LDD:
1) The MPX never had a manually-adjustable gas piston system, so if it is overgassing (the versions I shot did not have this issue) and they want to do something about it, they're going to have to come up with something new.

2) I did not see the charging handle droop issue with the early pre-production versions that I saw. I'll ask about this when I get the chance. SIG reads these threads so they are no-doubt aware of the issue. I'll see if I can get some commentary.

Thank you, LDD. Please keep us appraised of Sig's response to this issue.

I thought the original charging handle was supposed to be ambi as well. The slop is very noticeable and very unnecessary.

quote:

Originally posted by IrishWind:
So a piece of velcro loop in that spot won't help much? I hope Sig sees the is and is working on it.

I think that is a decent short term bandaid

quote:

Originally posted by burntorange98:
Great forum and thread, thanks.

1) Fwiw, the $165 Geissele G2S makes a world of difference, it's worth every bit.

2) What kind of cleaning interval do you guys think for the gas piston?

3) Has anyone else noticed brass shavings falling down into the trigger group area? I use factory Remington UMC ammo, so ammo quality isn't in question.

Thanks for any info on these.

quote:

Originally posted by burntorange98:

quote:

Originally posted by burntorange98:
Great forum and thread, thanks.

1) Fwiw, the $165 Geissele G2S makes a world of difference, it's worth every bit.

2) What kind of cleaning interval do you guys think for the gas piston?

3) Has anyone else noticed brass shavings falling down into the trigger group area? I use factory Remington UMC ammo, so ammo quality isn't in question.

Thanks for any info on these.

Yes does it in mine to.

NSWC-Crane bought 70 MPX-SD:
https://www.fbo.gov/index?s=op...e8&tab=core&_cview=0

And it looks like DoD paid about $202K:
https://www.usaspending.gov/Pa...=USA&k=N0016414CJN07

The contract was closed out on May 15th. Very interesting, perhaps for T&E, since no press/media release about this transaction? I wouldn't mind getting a factory MPX-SD, although Sig maybe reluctant due to the small market size for that specific configuration (think of their decision to only sell their fixed mount only suppressor to LE/GOV).

Not quite 3k/unit. But sure there are a lot of bells and whistles with item. Next question: Which Mk## will this be? Mk26? 27?

quote:

Originally posted by burntorange98:

quote:

Originally posted by burntorange98:
Great forum and thread, thanks.

1) Fwiw, the $165 Geissele G2S makes a world of difference, it's worth every bit.

2) What kind of cleaning interval do you guys think for the gas piston?

3) Has anyone else noticed brass shavings falling down into the trigger group area? I use factory Remington UMC ammo, so ammo quality isn't in question.

Thanks for any info on these.

I am getting the same shavings in my trigger group. Using target ammo.

The scaring on the upper from the charging handle is very disappointing for us guys who like to keep our equipment in top condition. I hope sig fixes the issue or someone makes a better aftermarket charging handle to take care of it. Would love a Raptor style handle on here.