Author Topic: 9mm AR vs. MPX/Scorpion (Read 7291 times)

AIM9X · « **on:** April 21, 2016, 09:19:24 am »

I am considering a new pistol caliber carbine and I am leaning toward an MPX because...well it just looks cool. (Also, it fires from a locked bolt, it has essentially AR controls, it's sort of compatible with aftermarket AR triggers, etc.).

Now, I have always shied away from 9mm ARs, mostly because I don't like the way they look with a skinny glock mag projecting out of a big magwell. But this is not really a good reason, particularly given that a 9mm AR can be had for less than half of what an MPX costs.

So, what advantages do these new wham-o-dyne 9mm carbines have over a 9mm AR?

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car-ram-rod · « **Reply #1 on:** April 21, 2016, 09:50:45 am »

I would go with the AR since there so simple to run, fix, change etc. but i havent run the scorpion yet. i may look into em soon

anm2_man · « **Reply #2 on:** April 21, 2016, 10:10:50 am »

I just converted my Tavor to 9mm. Could be another option.

DuneShoot · « **Reply #3 on:** April 21, 2016, 04:43:49 pm »

I have an SBR Scorpion and just sold a 10" 9mm AR upper.
AR Ego's are nice & familiar. Felt recoil was more on the AR. I also don't care for the looks of the AR's mags but that's minor.

I shot a friends MPX and it was nice, very comfortable. Trigger is heavy. Cost $1500'ish.

Scorpion is is around $800. Trigger needs at least new springs to lighten it up.
SBR kit is only $200.

Folding stock on the Scorpion and MPX is nice.

Chambered USA has a Scorpion in stock, didn't look at the price.

AIM9X · « **Reply #4 on:** April 21, 2016, 09:25:00 pm »

I just discovered that qc10, who builds pistol caliber ar components, is located here in baja arizona. That probably seals it for me.

cr · « **Reply #5 on:** April 22, 2016, 04:31:55 am »

I have the MPX and shoots great with any type of ammo. Yes it is pricey, but you can use some ar parts. I replaced the trigger springs with $10 JP springs and ended up with 41/2 lb. pull. It uses a piston system instead of direct blow back. This system reduces felt recoil by at least half. The Sig is built like a brick shit house with metal reinforcement in areas that wear.The difference from the Scorpion mags is that the MPX has metal reinforced lips. You can also change calibers w/ the MPX w/ just a barrel change. Barrel change is 2 screws and it is out.If price is a problem go with the Scorpion.

armoredman · « **Reply #6 on:** April 22, 2016, 12:14:49 pm »

I have a Scorpion EVO S3 pistol, with Thirdsen's cheek rest kit. It is the bomb. Never burped, mags are ridiculous cheap, and plentiful. Fun to shoot and accurate enough for this fat old man. It's my go to HD firearm right now. I did see an MPX in the wild finally at On Sight Shooting School in Casa Grande, with SIG Brace on it, didn't look at the price. I have heard mags are expensive but durable, and really hard to find, but I haven't looked. Most owners who have one are really happy with them. MAC did a head to head Scorpion vs MPX and the Scorpion barely came out on top, mostly due to the suppression issues with the MPX.
I like my Scorpion!

ynotaz · « **Reply #7 on:** April 22, 2016, 06:15:37 pm »

Scorpion $769 at PSA, CS custom in Mesa AZ, HD Industries $8.95 reduced trigger springs among other upgrade Chandler AZ, Scorpion 30 rounds Mags $30, 2016 model has 1/2X28 and old 18X1 threaded barrel.

High priced spread, SGC has one for $899

You can bling out an SBRed Scorpion with tax stamp for less than the price of an MPX.

Mine eats everything!

Bishop112 · « **Reply #8 on:** April 22, 2016, 09:19:41 pm »

I would look up the comparison on the military arms channel on YouTube. For me it would be a scorpion without a doubt. Sig has never done much for me.... little overpriced.

ynotaz · « **Reply #9 on:** April 24, 2016, 07:13:01 am »

If you plan on running a suppressor go with the Scorpion or an AR. The MPX has their own charging handle and there is no gas blocking version of it so it will spit at you if you run it supresed.

The Scorpion doesn't have this problem and you can get a "gas-buster" charging handle for a 9mm AR.

The military arms channel review makes this point very well especially when shooting supersonic through a suppressor.

PSA still has Scorpions for $769. they are the current version with the 18x1 threaded barrel not the newer 18x1 and 1/2x28 threads.

cr · « **Reply #10 on:** April 24, 2016, 03:45:27 pm »

You cannot believe everything you read on the net. I run my MPX suppressed and get no BLOW BACK what so ever.

armoredman · « **Reply #11 on:** April 24, 2016, 03:49:17 pm »

I'll never be able to afford a suppressor, so i don't worry about it. I just like to have fun.

ynotaz · « **Reply #12 on:** April 24, 2016, 05:45:26 pm »

Quote from: cr on April 24, 2016, 03:45:27 pm

You cannot believe everything you read on the net. I run my MPX suppressed and get no BLOW BACK what so ever.

Shooting as a pistol with arms extended should not be an issue. I just assumed folks would SBR a 5 pound pistol if they added another 3/4 to 1 pound at the front end for a can.

Blow back is VERY common for the AR design when suppressed. It happens to me in multi-calibers with both piston and DI guns when supressed.

You're also right not to believe what you read on the net but almost 2 million hits on "AR15 suppressed blow back" produce enough reading material that it must be considered before buying.

JesseL · « **Reply #13 on:** April 25, 2016, 04:51:24 pm »

Kinda apples and orangutans there.

An MPX looks kinda AR-ish, but it's very different. There's no gas tube for one thing, so any gas that comes back into the action is doing so through the barrel. An AR has the charging handle wrap around the gas tube, and any extra stuff that comes back from the tube is shooting straight at the handle. The MPX has no such direct route.

Then there's the fact that as a locked bolt 9mm, it's dealing with a much lower gas volume than any 5.56 gun and a lower breech pressure when the bolt opens than a straight blowback gun.

ynotaz · « **Reply #14 on:** April 25, 2016, 06:51:59 pm »

Sounds like the MPX gas system is totally different than any AR design, piston or DI, I have no MPX knowledge to disagree. Perhaps the cause is apples and orangutans but the blowback seems to be an issue defined by several respectable sources.

If a suppressor is not in the picture, this is a non-issue.

Tavorthom · « **Reply #15 on:** May 06, 2016, 02:39:02 pm »

Quote from: anm2_man on April 21, 2016, 10:10:50 am

I just converted my Tavor to 9mm. Could be another option.

How does it run?
Thom

AIM9X · « **Reply #16 on:** May 10, 2016, 07:55:02 pm »

Does anyone have any experience with the turkish mp5 clones?

ynotaz · « **Reply #17 on:** May 10, 2016, 08:04:21 pm »

I've shot the POFs and they run good. The fit and finish is not as good as the Zenith MKEs which also run well.

Keep in mind these are imported in large batches so a current batch could be better or worse.

6.5 Gunner · « **Reply #18 on:** May 10, 2016, 10:04:04 pm »

I love the MP5 (especially the K) I really wish someone other than Pakistan or Turkey would make an MP5 clone, I heard rumors that HK is actually going to "grace" us with an MP5 pistol for a small entry fee of 3700 smackers. Hurry up PTR and make one already!

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