SIG MPX

[USCSBarney]

All the ones I saw at Lucas ran like a champ. Don't know one person with one that regrets it. Still love my JP though. 

[NervousEnergy]

Question for MPX owners who've also shot AR9s in comp (USPSA mainly, though I'll admit to shooting the new provisional PCC division in IDPA as well):  If you had to do it all over again, would you stay with the MPX system or go AR9?

 

I've been shooting an X95 since March and having a blast with it - over a dozen matches and one major.  The gun has some major benefits, with reliability being the biggest.  I've had one jam in 4 cases of ammo and two charging handle reaches, where most other guns seem to be plagued with problems every other match.  I'd assumed the bullpup design would be a major benefit for the tight courses we seem to get here in the DFW area clubs - lots of hard angles, low portals, and other tricky shooting positions, and it may be... but after watching many other PCC shooters and running a couple of courses with a mates MPX last month, I've come to the conclusion that the sacrifice in transition speed with the bullpup is too much of a negative.  It simply takes longer to settle the dot when the weapon is tucked in tight to your torso than when you can drive the barrel with a hand way out away from your body, and it's harder to stay accurate when trying to go fast or shooting on the move.  The mechanical advantage of the hand clamped way out on a full length gun seems decisively better.  The X95 is also even heavier than the already heavy MPX.

 

I'm intrigued by the idea of building out a pistol MPX with the ULW Taccom barrel.  One other thing the X95 is amazing for is left-handed shooters, and the MPX delivers here just as well.  Not so much in the AR9 world.  OTOH, building out a light-weight AR9 is pretty trivial with quality parts available from dozens of vendors.  The Lead Star skeletonized upper/lower combo in particular looks great, coupled with an ULW barrel.  It'll likely have a lot more jump, though, compared to the .22 feeling MPX.  The MPX build would cost quite a bit more, but that's a pretty trivial distinction given the cost of all the ammo either gun will burn through in it's life. 

 

I know I'm posting in an MPX thread so the response will be somewhat biased, but I figured if there were MPX owners who didn't think the platform was worth the quirks compared to the AR9 they'd speak up here.  Sticking with the X95 through next January at least when it's bonus time, but then I'm going to try something different.  Just not sure what.  I'm at best a low B shooter with the X95, and while most of that is me (it's always the injun, not the bow) I did get a significant bump in time shooting the same course with a full length carbine than I did the X95, based entirely on how quickly and confidently I could transition targets.

[Aircooled6racer]

Hello: Having started with a Mech Tech Glock 9mm many years ago and doing well with it, then building a couple of AR9mm with Colt and Glock mags. Now I have a built out Sig MPX 8" pistol with Taccom 9" welded extension. I can tell you that I have also shot some other really cool PCC's as well like a MP5 clone, Vector and a CZ. The Sig will cost you more than the rest. Is it better? I have not shot it enough yet to really say one way or the other. The Sig will cost about $500-$1000 more than a pretty good AR9mm home built with top shelf parts. The Sig shoots pretty soft but my splits are about the same as the AR9mm, same trigger in both. I am still playing with weight on the Sig and have the AR9mm figured out for me. Loads for each are different. The Sig seems to like lighter bullets going a little faster, where the AR9 likes heavier bullets going slower. The buffer and bolt setup on the AR9 are important if you want it to shoot flat. The Sig I have not tried any other springs yet so I won't know till that happens. Now for the short barrel SBR setup. I don't have a SBR but I shoot with a young guy who does. He just built up a 16" barrel upper for that lower and is doing better with it than the 4 1/2" barrel. I do see an advantage if the courses of fire are really tight where the SBR would be better but maybe not that much better. We have some really good PCC shooters here who seem to do really well with there 16" barreled guns. Here is a pic of one of my Sig MPX setups with the long hand guard. I also have the original 8" and a 10" as well. I will be testing all three later this week. Thanks, Eric

[tyler2you]

I've got an SBR'd MPX and an AR-9.  I shoot the AR-9 better in most situations.  I'm quicker and more confident on transitions due to the longer handguard as mentioned.  I have also been able to tune the AR with recoil components and loads to run quick with consistent dot return.  Those same loads make the MPX sluggish (heavy bullet, fast powder).  I need to do some more experimentation with lighter bullets in the MPX to see if I can get it to run to my liking.  Here's my quick take/experience on each platform:

 

MPX (SBR):

- Expensive

+ Very low recoil implulse

+ Short barrel excels around tight obstacles

- Limited ability to tune the recoil system

- Limited aftermarket trigger options 

- Slightly complex gas operated system

- Running coated bullets leads up the gas valve and tappet

- Less tolerant of running dirty

+ Excellent/reliable magazines built by Lancer

- Slower for me to reload

 

AR-9:

+ Less Expensive

- Slightly harsher recoil impulse

+ Extensive tuning options (buffers, recoil springs, etc.)

+ Quicker/more confident transitions with longer handguards

+ Lots of trigger options (although some can have reset issues or double depending on the bolt)

+ Simple blowback operation

+ More tolerant of running dirty

- Fragile firing pins

- Magazine system adapted from other platforms, requires optimal feed angle and barrel opening

+ Faster for me to reload with pistol size magazines

 

 

 

[NervousEnergy]

Thanks for the input!  I should mention I was thinking of starting with the MPX pistol to save a bit of up-front cost since I would be replacing the barrel with the Taccom ULW 16" and the brace with a full stock.  I wouldn't SBR it.

Quote

The Sig shoots pretty soft but my splits are about the same as the AR9mm

I've heard this now from several folks, and it surprises me.  I'd think a softer recoil impulse would naturally result in faster splits.  I loved the soft recoil impulse on the MPX carbine I ran through a course, but if it's not going to result in any appreciable difference in the timer at the end then that takes away a major reason to spend the $$ on the MPX platform. 

 

Though I'm still left with... the left.  I shoot left handed (one of the cursed cross-dominate folks), and the MPX, like my Tavor, is 100% lefty friendly.  Not so much the AR9 family.  Even with a Troy ambi mag release on my JP-15, I find it somewhat awkward to reload compared to the X95.  Reliability also seems iffy on both the MPX and AR9 platforms... I've won more than few stages when guys faster than me had to clear a malfunction, while my X95 just runs and runs. 

Edited October 10, 2017 by NervousEnergy

[Aircooled6racer]

Hello: Since you are left handed I think I would go the MPX 8" pistol version. Get the 9" Taccom extension(have it pinned and welded), Thordson AR stock adapter, Mil Spec AR15 buffer tube and castle nut, AR stock you like and maybe a grip. Slap a C-More railway on top and you are ready. That is what I did and I am quite happy with it. I have not shot it enough yet to say it is better or worse than an AR9mm. If you want a plug and play than it maybe a better way to go or get a JP. Thanks, Eric

[CaptRight]

Question for you guys in the know. I am about to gamer out my MPX as PCC is just too much fun. What is better for recoil and transitions ILWT 14.5” barrel + Taccom comp, or taccom ULW barrel? If taccom ULW barrel, with or without the mid brake?

[Aircooled6racer]

Hello: I went the Sig 8" pistol route with a Taccom(no break) 9" extension that I pinned and welded. I have not shot a stock 16" barrel Sig back to back with mine. I have noticed that a little more weight forward actually is faster for me than being very light using 115 grain bullets at 135PF. Mine transitions just great since mine has more of the weight in the stock and receiver. For USPSA pistol matches I am not sold on the ultra light setups. For steel challenge go with the light setup. For 3-gun go with a scope that is 1-3X or more. Thanks, Eric

[troupe]

I have shot both in comp. and the Sig is the best game gun going. It has done wonders for me and I am a average shooter. I have average 7 to 10 places higher with the Sig. Shot confidence is much better for me.

[Aircooled6racer]

Hello: Sig have the Gen 1 mags on sale for $14.99 for the 30 round and $8.99 for the 20 round mags. These are working 100% in my Gen 2 but your mileage may vary. Thanks, Eric

Edited October 14, 2017 by Aircooled6racer

[Aircooled6racer]

Hello: Does anyone make an extended right side mag release? Thanks, Eric

[jarozzy]

On 10/13/2017 at 7:15 AM, Aircooled6racer said:

Hello: I went the Sig 8" pistol route with a Taccom(no break) 9" extension that I pinned and welded. I have not shot a stock 16" barrel Sig back to back with mine. I have noticed that a little more weight forward actually is faster for me than being very light using 115 grain bullets at 135PF. Mine transitions just great since mine has more of the weight in the stock and receiver. For USPSA pistol matches I am not sold on the ultra light setups. For steel challenge go with the light setup. For 3-gun go with a scope that is 1-3X or more. Thanks, Eric

Do you have a pic of what your gun looks like with the 9" extension?

thanks

[Aircooled6racer]

1 hour ago, jarozzy said:

Do you have a pic of what your gun looks like with the 9" extension?

thanks

Hello: Here it is again. Thanks, Eric

[Canman]

Just traded for this one. Might SBR it. Who make the thinnest handguard for it?

[Aircooled6racer]

55 minutes ago, Canman said:

Just traded for this one. Might SBR it. Who make the thinnest handguard for it?

Hello: I think Taccom make the smallest diameter hand guard for the MPX right now. I thought I would not like the large diameter hand guard but it is not that bad I am finding. I would shoot it first before you decide to make it a short barreled rifle. Thanks, Eric

[MHitchcock]

Depending on your grip you may want to find a stock or stock type handguard (such as the Midwest industries) when/if you SBR it. The rail extends over the piston and with shorter handgaurds for 8" or under barrels I have found the smaller diameter handguards impossible to use due to the drop off.

[troupe]

If you are a longer armed person, move your finger stop on the bottom forward, get a better trigger, which you would do anyway, put a better stock on it, a red dot and roll with it. It will be a winner for you. I shoot the Federal 115's in mine and it is awesome.

[Tonka]

Ive been shooting my MPX now for several months, I had the JP and the mectec to start but sold them when I got the mpx.  I have finally settled on what loads that I like to shoot, but they all worked well.  I was using the montana gold 147's with different powders and they worked fine.  I did have a comp put on it by springer precision and now I use the Montana gold 121's the same bullet that I use in my open pistol.  I put 4.2 grains of 320 behind it and get a 133 power factor.  This load is very soft and flat..

[ThisIsMyBoomStick]

I have been shooting this SBR MPX for about 7 months now in USPSA and Steel Challenge with an 8" barrel. I have tried several different configurations. This setup with a 4" barrel is the latest mod:

 

 

Shot it at a steel match this week for the first time with the 4" barrel and I like it much better than the 8" setup. Placed 3rd, with 1st and 2nd going to PCC shooters as well. Local paper match next week to try out the new CT laser. Will be handy for a few situations..

Edited October 28, 2017 by ThisIsMyBoomStick

[SergioSF]

Just got my barrel cut/threaded/pinned/welded to add the @TRUBL 11-inch extension. With the barrel shortened, I got the gas port opened up even further too.

 

This thing feels feathery light now. Can't wait to see how we do at this weekend's match. Surely these updates will bring me from mid-pack to UPPER mid-pack!

 

[Honeybooboo]

On 11/1/2017 at 10:42 PM, SergioSF said:

Just got my barrel cut/threaded/pinned/welded to add the @TRUBL 11-inch extension. With the barrel shortened, I got the gas port opened up even further too.

 

This thing feels feathery light now. Can't wait to see how we do at this weekend's match. Surely these updates will bring me from mid-pack to UPPER mid-pack!

 

 

What hamdguard is this?

[Aircooled6racer]

14 minutes ago, Honeybooboo said:

 

What hamdguard is this?

Hello: Looks like a Lancer to me. There are a couple of other options out there and I am sure more to come in the new year. Thanks, Eric

[SergioSF]

Yes, Eric's right - it's a Lancer. (14") (https://lancer-systems.com/awc/carbon-fiber-handguards/)

 

Tim at Taccom makes one (https://taccom3g.com/product/taccom-mpx-handguard/)

And so does Mark Isler (https://www.islercustomgunworks.com/custom-parts/)

[Honeybooboo]

The Lancer is slickkkk. Do you notice a lot of weight difference?

[SergioSF]

14 minutes ago, Honeybooboo said:

The Lancer is slickkkk. Do you notice a lot of weight difference?

 

From the OEM boat anchor? Yes, huge difference in weight and swingability.

And the grip is a little slimmer too, because of no top rail.