Mpx vs Ar9

[reballz]

So I shot an Ar9 all last year. Shot an mpx last weekend and fell in love. Looking for honest opinions from people who have run both. A buddy has told me about a few issues with the mpx regarding gas port flame cutting, extractors, etc.... I’m looking at the new gen 3 Pcc model. Also I don’t care about the magazine prices lol.

 

 

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[ABQautoxer]

Nothing will have less perceived recoil than the MPX. If thats what you find enjoyable, its for you. I avoided it do to our local GM just struggling to keep his running while I never have an issue with my AR9.

[Startingover]

I try to avoid shooting them!

LOL 

It just makes my Kronos feel like a bazooka everytime afterwards!

[Gregg K]

I have an AR9 and thought I had it where no more improvements could be done, thought that it was extremely soft shooting, them I shot an MPX. I ordered one the next day and have been shooting it since. Every once in a while I'll take them both out and shoot them side by side and then I kick the AR9 back to the curb again.

I have had no issues with my MPX shooting a wide range of power factors. It cycles just fine on 95 grain 93 PF loads too.

 

OK, I had one issue with the MPX, the trigger sucked so I replaced it with an Eclipse, problem solved. You will clean it a little more than the AR.

[reballz]

I have an AR9 and thought I had it where no more improvements could be done, thought that it was extremely soft shooting, them I shot an MPX. I ordered one the next day and have been shooting it since. Every once in a while I'll take them both out and shoot them side by side and then I kick the AR9 back to the curb again.
I have had no issues with my MPX shooting a wide range of power factors. It cycles just fine on 95 grain 93 PF loads too.
 
OK, I had one issue with the MPX, the trigger sucked so I replaced it with an Eclipse, problem solved. You will clean it a little more than the AR.

I will definitely be buying an eclipse if I do this.


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[Rolex]

Blow back is just old school. Good when it was out.

MPX with gas ports is the future for 9mm PCC.

I have had two MPXs never had an issue with either one.

[Bwillis]

I’ve shot 2 mpxs and I’ll take my franken9 all day long and twice on Sunday. One shooter m class has all kinds of trouble with his mpx. Another A class guy his will shoot anything and never had an issue. I don’t like cleaning guns for one and I like having a vast aftermarket product support for whatever part I might be changing that week. Sig mpx offers me neither 

[Fasthenk65]

You guys... within weeks I have both and can make my own judgement

 

[Neomet]

One thing for you to remember when listening to opinions here, specifically about reliability issues with the MPX.  The Gen 3 is not a Gen 2 or a Gen 1.  At a minimum, it has a different bolt carrier assembly, different gas port dimensions and a different barrel all of which play into the issues some had with the MPX.  Put the most value on input from those with a Gen 3.  That said if both are reliable as a rock I think the MPX is significantly better and I have a JP GMR in the safe as well.  I have a Gen 2 and when I quit trying to find the perfect 125.1 PF load and just shot either factory or reloads at 140 PF or so I quit having problems and the gun still has far less dot bounce and recoil than any blowback. but again, this is with a Gen 2.

     

[ABQautoxer]

It doesn't matter, everyone has their own opinion and experiences. You'll have yours and pick your choices. This thread in the short time I've been on this section of the forum has come up a lot.

[Acer2428]

Yep, use the search, it's been hashed and re-hashed.

 

The MPX is super soft and chews through full power/factory ammo. IMO get a Gen 1 or a 'Gen 3'/PCC model. I have two Gen 1's that have been great. Don't mix generations/mags. Yes, they CAN be made to work together, but why risk a FTF for $20?

 

Neither one is going to make or break you. Practice, practice, practice. 

[Rolex]

AND stop changing parts out on the MPXs- leave them stock= no problems!

[edwin garcia]

Try both, ask local shooters to try their PCCs. They both can be reliable and fun to shoot. Most of these qualities are shooter preference at the end of the day.

In fairness, I've seen a fair share of AR9s that fail, too. Any platform will potentially have issue. The key is knowing what's worth changing (ammo, parts, accessories, etc.) and what not to touch. Some PCCs run out of the box, but most IPSC/USPSA shooters will tend to tweak their platform sooner than later.

 

I started with JP (no complaints, excellent almost every aspect) and ended up with a Sig MPX G2. Several factors made me keep the Sig. I come from Open Div so I like pushing my equipment. Cleaning frequently is an ingrained routine. I like it clean. Cool factor, magazine is curved. I think mags with more than 15 round should have a curved configuration, just my opinion.

 

Either way, get what fancy you most and make it work. Shooting season has started here in the south and it'll be over with before you know it.

Cheers!

 

[reballz]

Try both, ask local shooters to try their PCCs. They both can be reliable and fun to shoot. Most of these qualities are shooter preference at the end of the day.
In fairness, I've seen a fair share of AR9s that fail, too. Any platform will potentially have issue. The key is knowing what's worth changing (ammo, parts, accessories, etc.) and what not to touch. Some PCCs run out of the box, but most IPSC/USPSA shooters will tend to tweak their platform sooner than later.
 
I started with JP (no complaints, excellent almost every aspect) and ended up with a Sig MPX G2. Several factors made me keep the Sig. I come from Open Div so I like pushing my equipment. Cleaning frequently is an ingrained routine. I like it clean. Cool factor, magazine is curved. I think mags with more than 15 round should have a curved configuration, just my opinion.
 
Either way, get what fancy you most and make it work. Shooting season has started here in the south and it'll be over with before you know it.
Cheers!
 

I shot an ar9 last season. I loved it until I shot one of the new gen 3 mpx’s. That thing was amazing!


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[Aircooled6racer]

Hello: I have had 3 MPX's and a couple AR9's. The MPX does shoot softer but I am not sure it is any quicker than a well setup AR9. Both can win in the hands of someone who practices with them. For me I really don't like cleaning that much but must say the MPX's I had ran great even though they were very dirty. I took them over 1200 before cleaning and the only reason I cleaned them was I felt guilty. I still have my AR9's since I can play around with different setups with them. One is a QC10 Glock lower and the other is a QC10 Colt style lower. The MPX's are now in other hands who are still enjoying them. Thanks, Eric

[Polaris13]

I've stated this on other posts, but since this is a new post on the same subject, I'll go over it again.  I have a Gen 2 MPX and a home built AR9 with JP guts that is sorted out over two years.  I bought the MPX, put a Hiperfire 24C trigger in it and went shooting.  The MPX eats anything with no complaints or hiccups.  It also is a soft shooter.  My AR9 shoots just as good as the MPX but it has taken time and money to get it that way.  If I was doing it all over again with the knowledge I have now, I'd buy the MPX, put a HIperfire trigger in it and go shooting without the tuning and testing that my AR 9 needed.  It would be faster and cheaper in the long run.  That being said, I'm quite geeky, so the long tuning process of the AR9 was quite fun, but time consuming.  And yes, the MPX does take a bit more time to clean.  I hope this helps you with your decision.  Good Luck.  As a side note, I put Ultradot Match Dot 2 optics on both guns.  Yes these aren't as light at a small red dot, but their versatility and quality do it for me.  Another 2 cents.

[reballz]

I've stated this on other posts, but since this is a new post on the same subject, I'll go over it again.  I have a Gen 2 MPX and a home built AR9 with JP guts that is sorted out over two years.  I bought the MPX, put a Hiperfire 24C trigger in it and went shooting.  The MPX eats anything with no complaints or hiccups.  It also is a soft shooter.  My AR9 shoots just as good as the MPX but it has taken time and money to get it that way.  If I was doing it all over again with the knowledge I have now, I'd buy the MPX, put a HIperfire trigger in it and go shooting without the tuning and testing that my AR 9 needed.  It would be faster and cheaper in the long run.  That being said, I'm quite geeky, so the long tuning process of the AR9 was quite fun, but time consuming.  And yes, the MPX does take a bit more time to clean.  I hope this helps you with your decision.  Good Luck.  As a side note, I put Ultradot Match Dot 2 optics on both guns.  Yes these aren't as light at a small red dot, but their versatility and quality do it for me.  Another 2 cents.

I hear you on the ar9 r&d. Luckily I have a couple of buddy’s that love that s#!t so I basically bought most everything they run on the ar9. The mpx I shot a couple of weeks ago was so nice. Loved my load. I run the holosun 510c on my Pcc.


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[ChuckS]

I worked the Barry's Steel Open in St. George this year. The match had 97 PCC shooters and I probably ran about 70 of them on our stage.

My non-scientific (I didn't take notes since my job was to run the stage) observations are:

 

1) MPX malfunctions were more common than AR9 malfunctions.

(This was a 2 day, 650 round match in a dusty environment. Perhaps a blowback could muscle through were a piston gun had issues)

 

2) The majority of obvious Glock-style magazine problems had MBX extensions.

(Just trying to stack 50-60 tapered case rounds in a straight mag tube is really pushing it. The curved mag tubes are an advantage)

 

So what I came away with was neither platform is perfect.

[reballz]

Mpx Pcc has been ordered. thanks everyone.


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[Startingover]

14 hours ago, reballz said:

Mpx Pcc has been ordered. thanks everyone.


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Another one has gone to the dark side!

If you ever start to miss your Kronos, you can shoot one of mine, then you will remember why you wanted the mpx.

LOL 

[Descartian]

So if I’m not mistaken from reading the above posts, the Gen 2 has done issues and if I’m looking or an MPX I should be looking for a Gen 3. 

[reballz]

So if I’m not mistaken from reading the above posts, the Gen 2 has done issues and if I’m looking or an MPX I should be looking for a Gen 3. 

To my understanding, sig has taken care of the major issues on the previous versions with the gen 3. I’m gonna give it a shot. If it ends up being a turd, whatever.


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[NervousEnergy]

Gen 2 was fine, with a few early QC exceptions (feed ramp mis-alignment, etc.)  You still will definitely want a Gen 3, though, until a new (or very lightly used) gen 2 drops down to a grand or less.  You get a ton of stuff in the gen 3 that you'll pay extra for with a 2.  Trigger, barrel with comp, better handguard, better stock, etc.  I got an MPX pistol for $1100 new off Gunbroker early last year as that was the cheapest way to get into the gun, since I knew I'd replace virtually everything other than the upper and lower.  After the hiperfire, ILWT barrel / guard, fixed tube & stock, it was still more than a new Gen 3 is now with all that stuff.  You may still want a different tube/stock (I hate folders... they usually wobble a bit), but the rest is all good equipment.

 

Here is a pretty in-depth review of the Gen 3 MPX PCC vs the earlier MPX Carbine by a competition shooter:  

http://thrumylens.org/featured/review-of-the-sig-mpx-pcc/

 

 

[tanfoglio1911]

I just got my MPX PCC, will test it this week and will run it in the match this weekend. I ordered a magwell and magazine extension for this thing. Working on my reloads this time and need some help in regards to OAL. Thanks.

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[fbzero]

I just got an MPX PCC this last Friday and got to shoot it side by side with the tweaked CK Arms AR9 that I shot last year for the first time on Sunday.   Mind you, I have made modifications to the AR9 and this MPX is completely stock.  Ultimately, you have to decide what you will prefer the most, but here are my thoughts...

*The first couple items might sound a bit like I'm bashing on the MPX, but I promise I'm not.  I'm simply comparing a stock PCC to one that is well tuned.  

1.  The Timney trigger is better than most stock triggers, but seems a bit heavy to me.  I've been spoiled by Hiperfires on most rifles in the house and one Triggertech, so that may not be the case for you.  While I can shoot somewhat fast with it, if I try to go as fast as I can with a Hiperfire, I end up with a hiccup nearly every time.  In comparing the two rifles, this created some difficulty getting what I consider a "direct" comparison on the timer.  My times were close though, and that surprised me given the unfamiliarity with the MPX, heavier trigger, and heavier front-end - which brings me to #2.

 

2.  They shaved a pound off of the newer release, which is significant.  Even so, the way it comes is front heavy.  This doesn't seem to be because the front is actually heavy, but because the stock is light.  People prefer their rifles balanced differently; I prefer mine either a bit back heavy or balanced at the magwell.  My AR9 uses the Taccom ULW barrel, so there is basically no weight in the front.  This makes my AR9 swing with less effort.  I suspect that an AR-15 stock adapter with a heavier stock that has a better cheek weld would rectify this if one thought it was necessary.  

 

3.  Most people who like the MPX seem to point to the lower recoil, and that seems warranted from what I can tell.  As mentioned, my AR9 has been tuned to what feels and performs good to me with my reloads.  That's a 3-stage Taccom3G buffer, JP AR-10 buffer spring, and 8 quarters behind that spring to "short stroke" it.  Even with all that tuning, I do think that the MPX recoiled a bit softer - completely stock.  My only complaint was that the cycle seemed to take slightly longer, which made it just a pinch harder to track the dot for me.  I do not believe this is a deficiency in the MPX, but the result of my reloads not being optimal.  It was only locking back about half of the time and I had one or two feed issues that seemed to be caused by a short cycle.  Perhaps they will be enough once broken in with some hotter ammunition, but at least out of the box, I do not believe that my 135gr 133PF reloads have quite enough "oomf" for 100% reliable cycling.  I'm also using the standard heavier bullet/faster powder that is nice for pistols (and my pistol length ULW AR9 with no comp)...a slower powder that builds up more gasses to work the comp might make the MPX recoil seem even lighter.

 

4.  Another area I have to hand to the MPX is magazine seating.  Maybe this is something I just haven't learned how to get just right on my AR9, but with a magazine that is full or mostly full, it takes more effort than I like to reload.  This doesn't matter on most stages since you just do it somewhere that you have plenty of time, but that is never the case with classifiers.  Even when full, the MPX magazines insert easier, which should be nice for classifiers.

 

5.  It works, but I don't like the bigger handguard, even though they made it smaller on this newer model.  I hope that Taccom3G makes one of their thinner carbon fiber ULW's for it, because I'd switch for one of those in a second.

 

6.  I cannot make any determinations for reliability yet, particularly since my reloads may not be hot enough.  By all accounts, however, due to the gas operating system the MPX will require more cleaning to keep it reliable.  The only hiccup I've really seen from my AR9 is a battered firing pin(from the Hiperfire 24C most likely) and magazine failures.  The blowback design gets the top area of the Glock magazines dirty fast and they need to be cleaned frequently(every other match, or halfway through a big match) to make sure that doesn't end up causing issues.  That is actually the only failure I have ever experienced at a match(knock on wood), and my wife and I shared it at the Lucas Oil PCC match last year.  We also shot Friday in the rain and all I did was a quick field clean halfway through.  Surprised me, given the amount of PCC's that were going down...

 

Anyway, hope some of that helps.  While there are some changes I'm likely to make on the MPX, I am impressed with it fresh out of the box.  The AR9 *needed* tuning before I was happy enough to run it in a match.  With hotter ammo, I'd be perfectly happy taking the MPX to a match straight out of the box, even if I did make some changes eventually.
 

 

 

Edited April 22, 2019 by fbzero