Sig MPX?

[ranger]

@ranger Thanks. Is it the ILWT barrel ? Also copper or silver/aluminum anti-seize ?

I use the OEM 8 inch 95% of the time. The 4.5 inch barrel is the ILWT and I use it with an AAC TiRant 9 with the OEM handguard.

I use the copper anti-seize in a tube. Put some on the piston after cleaning as I reassemble.

[HCM]

I use the OEM 8 inch 95% of the time. The 4.5 inch barrel is the ILWT and I use it with an AAC TiRant 9 with the OEM handguard.

I use the copper anti-seize in a tube. Put some on the piston after cleaning as I reassemble.

That stuff gets EVERYWHERE but I may have to try some.

[ranger]

That stuff gets EVERYWHERE but I may have to try some.

Yes, I use a Q tip to minimize issues.

[JCN]

Sunday @JM Campbell and I got to shoot on a friends property and I took the opportunity to try a variety of loads in my 8' gen2 MPX before detail stripping and cleaning the gas piston. Each was a 25 round magazine:


1) Blazer 115 grain FMJ - multiple malfunctions
2) Speer Gold Dot 124 grain +P - No malfunctions
3) Speer Lawman 115 Grain +P FMJ - No malfunctions
4) Federal Synthtech 150 grain Coated Truncated Cone - Multiple malfunctions
5) Winchester Ranger 147 grain bonded JHP - Multiple malfunctions
6) Federal American Eagle 124 grain FMJ - No malfunctions
7) Federal White box (LE Contract) 147 grain TMJ (truncated cone) No malfunctions
8) Magtech 115 grain FMJ - No malfunctions

It seemed the hotter the ammo the better it ran and it seemed to work best with the +P stuff.

Anyone else had similar experiences with their MPX ?

I've got a few thousand rounds on the gun (Mostly Magtech 115) so I'll try and repeat this after cleaning the gas piston and compare results.

@Clusterfrack didn't you mention using anti-seize of the piston in one of the PDW threads ?

My agency has adopted the MPX and just issued a 9 page cleaning and maintenance procedure which includes cleaning the gas piston.

Another thought:

Has anyone seen differences in reliability between the 4', 8' and 16' barreled variants ?

I recently saw a MAC video (I know) about issues he had with a new MPX and the how using an MI taper adapter effected accuracy. He tried to buy a taper adapter from SIG but they stopped selling them and SIG CS could not tell him why. He speculated maybe SIG knew about the taper adapters causing issues and quietly discontinued them. This got me thinking about SIG discontinuing the 8' MPXs. In the recent TFB interview with a SIG executive, they asked why the 8' was discontinued. The reply was that " SBRs dont sell" which was curious as I'm sure most of the 8' MPX SIG sold were brace pistols. I'm curious as to whether SIG discontinued the 8" because the 4" guns ran better ?

If work hadn't adopted these I'm pretty sure I would have traded it in on an APC PRO by now.....

Bumping this up for updated thoughts on weak gamer ammo. I know a lot of factory springs can be too stiff with gamer
ammo, ordered an 8” and looking forward to learning it.

[JCN]

Like every time I learn a new platform there are idiosyncrasies…

Doh Sig for making a 13.5LH thread! WTF man.

The only thing I have in that is:



Which might be enough back pressure to help cycle gamer 9mm?

[HCM]

Bumping this up for updated thoughts on weak gamer ammo. I know a lot of factory springs can be too stiff with gamer
ammo, ordered an 8” and looking forward to learning it.

Check out In Lead We Trust for options. Still haven’t cleaned that gas system.

The newer 4.5” guns don’t seem to be as ammo sensitive and my older /early Gen 2.

The mag tech 115 is not super hot but seems to run fine.

It seemed like it didn’t like 147-150 grain or flat nose profiles.

[JCN]

Check out In Lead We Trust for options. Still haven’t cleaned that gas system.

The newer 4.5” guns don’t seem to be as ammo sensitive and my older /early Gen 2.

The mag tech 115 is not super hot but seems to run fine.

Thank you! I also found this Enos thread

https://forums.brianenos.com/topic/2...-eject/page/2/

And bought some of the BCM O-ring and spring for extractor

[HCM]

Thank you! I also found this Enos thread

https://forums.brianenos.com/topic/2...-eject/page/2/

And bought some of the BCM O-ring and spring for extractor

If you were buying a new production gun you may not need any of that.

Sigg does not acknowledge a GEN three MPX but in my experience the latest 4.5 inch and 16 inch guns which come from the factory with MLOK hand guards straight Timney trigger run noticeably better than the older Kimon handguard era GEN 2 guns.

I’ve actually thought about cashing out of this older gun and picking up a new 8 inch LEO model. Seguin is definitely one of those companies that shows a higher standard of care in terms of parts assembly and overall QC for their IOP line products.

[JCN]

If you were buying a new production gun you may not need any of that.

Sigg does not acknowledge a GEN three MPX but in my experience the latest 4.5 inch and 16 inch guns which come from the factory with MLOK hand guards straight Timney trigger run noticeably better than the older Kimon handguard era GEN 2 guns.

I’ve actually thought about cashing out of this older gun and picking up a new 8 inch LEO model. Seguin is definitely one of those companies that shows a higher standard of care in terms of parts assembly and overall QC for their IOP line products.

I can’t tell but I was just figuring if it was an 8” it probably wouldn’t have all the current upgrades?



Mlok plus curved trigger?

[JCN]

ILWT: tuning spring pack (maybe +20% for Syntech 150)
BCM: extractor kit
TTI: magwell, +10 basepads, springs and compensator
MGW: Timney trigger
Osage County: 30 round magazines

This will mainly be for recreational gaming.