Reader Eric writes:
You guys have reviewed the new CZ Scorpion and the SIG MPX separately. Is there a chance you could do a direct comparison between the two? That would be awesome.
I reviewed both the SIG SAUER MPX and the CZ Scorpion EVO 3 Pistol, and while I think I’m an impartial judge of the two guns I wanted to take that a step further. Following the release of these two guns, Jeremy S. purchased a Scorpion and I purchased my very own MPX. So I asked Jeremy to join me in a quick head-to-head review representing the Scorpion side of the argument, and I’ll be handling the MPX. Let’s get ready to rumble! . . .
Scorpion (Jeremy S.): Angular and futuristic.
MPX (Nick): Sleek and familiar. It looks just like a midget AR-15.
Scorpion (Jeremy S.): Nearly everything visible on the outside is polymer. Barrel is cold hammer forged. Most other metal is forged or machined from bar stock. The bolt is over 1.4 lbs of solid steel.
MPX (Nick): The gun is mostly aluminum, with some steel inserts and other metal bits. It feels solid, not like the mostly plastic Scorpion.
Scorpion (Jeremy S.): Straight blowback. Simple and as reliable as it gets. The heavy bolt provides a nice delay to the action and definitely reduces gas and debris blockback through the breech.
MPX (Nick): The short stroke recoil system means the bolt is much lighter, and therefore there’s less moving mass to throw off your shot. It might complicate the operating bits somewhat, but it means a lighter spring in the gun and a lighter recoiling firearm in my opinion.
Scorpion (Jeremy S.): 10-, 20-, and 30-round magazines are available. Full MSRP for the 30-rounders is $19.95, and the other two run $17.95. All polymer except for the spring. Translucent body.
MPX (Nick): The gun ships with a 30 round magazine, 10 and 20 round versions coming soon. Mags are made by Lancer, a company who makes the only mags I trust for hunting. Like the Scorpion they are proprietary, but Lancer has a great track record for mag manufacturing. Way more expensive than the Scorpion though — $55 a pop.
Field Stripping & Cleaning:
Scorpion (Jeremy S.): Lock bolt back. Push out one captive pin by hand. Pull trigger housing off frame. Pull bolt out of frame. Done. Video.
MPX (Nick): If you’ve cleaned an AR-15, you can clean the MPX. Pull the rear takedown pin and the guts fall out. Pull the forward takedown pin and the handguards slide right off, revealing the barrel and gas system for an easy wipedown.
Available Options (barrel length, stock, etc):
Scorpion (Jeremy S.): Currently only available in pistol form with 7.72″ bbl. Optional AR-15 buffer tube adapter allows for mounting of a pistol arm brace or, with SBR registration, any AR-15 stock. CZ-USA will be selling a 922(r) compliance kit and the factory Scorpion Evo SMG stock in late summer. Once 922(r) compliance is assured, I expect CZ-USA will begin selling carbine versions and possibly factory SBRs. Maybe in time for Black Friday shopping?
MPX (Nick): Right now, the gun is only available in the 8″ barrel variety. You do, however, have the option of buying the gun with a customized pistol brace already attached that looks very slick. Coming soon, the gun will be available with a 4.5 inch barrel as well as a 16 inch option for those wanting a true rifle, and those barrels will be available as after-purchase options from SIG SAUER. Also coming soon are a collapsible MP5 style stock, as well as a side folding stock fresh from the factory. No pesky 922(r) considerations on this all-American gun. Changing your existing gun’s barrel length is as easy as pulling the forward takedown pin and unscrewing two hex screws, easier than any other gun I own. Other than the Ruger 10/22 Takedown.
Scorpion (Jeremy S.): Non-reciprocating, forward charging handle, which can be moved to either side of the gun. Can also be used to lock bolt to the rear and then released with an HK MP5 style palm bump. An additional, thumb-activated bolt release is used for after the gun locks back on empty. Ambidextrous magazine release is a paddle on each side of the front of the trigger guard. Accessible with strong hand index finger (for speed reload) or weak hand thumb (for tactical reload). Ambidextrous, AR-15 style safety comes standard, but CZ-USA also sells a right-side safety delete for those who prefer a sleeker and less obtrusive non-ambi layout. Reach to the trigger and safety is adjustable by means of a pistol grip that slides back and forth on a rail. Cool idea that I haven’t seen before.
MPX (Nick): The controls are identical to an AR-15, with some exceptions. There’s a magazine release on both sides of the gun to allow lefties as well as righties to drop the mag for speed reloads. The bolt release is also ambidextrous, with a control input on the right side of the gun. That not only makes it easy for lefties to drop the bolt but also for righties to do everything with just their trigger finger. The charging handle is akin to a standard AR-15 charging handle, but the shorter size and the design makes it incompatible with replacements already on the market. It does feel a little flimsy unfortunately, but its familiar and functions just fine.
Scorpion (Jeremy S.): 7.72″
MPX (Nick): 8 inches on the dot. Or 4.5 if you wait. Or 16 if you wait longer.
Scorpion (Jeremy S.): 4.33 lbs (pistol, no magazine)
MPX (Nick): 6.1 pounds with SB Tactical pistol brace attached.
Scorpion (Jeremy S.): 10-ish lbs of battle trigger. Plenty of take-up, an acceptably crisp break, rather gritty overall, solid reset. It’s definitely breaking in as I put more rounds through my example (edit: after about 500 rounds it is vastly improved. Lighter and smoother). On the bright side, it’s a drop-in unit so aftermarket replacements will be very easy to install and, yes, they’re already in the works!
MPX (Nick): Ugh. Squishy and a bit heavy, just like the original MP5 trigger. Definitely not the best feature of the gun, but acceptable.
Scorpion (Jeremy S.): From a sandbag rest at 25 yards with a 4x scope on it, I shot 6, 5-round groups with 5 brands of ammo and every last one of them was a single, ragged hole. The best group, which was shot with American Eagle 147-grain FMJ through the Liberty Mystic suppressor and is pictured below (HST round just for scale), was barely over a half inch. Yes, there are 5 rounds in that hole:
MPX (Nick): From 15 yards with some crappy ammo, the gun shoots damn near one-hole groups. I’d say the accuracy is pretty much a wash between the two guns.
Scorpion (Jeremy S.): Almost every part of the Scorp is covered in picatinny rail. The whole top of the receiver is railed, and that top rail continues onto the handguard. The other three sides of the handguard are railed as well. It even comes with a hand stop. With swappable receiver end plates, I wouldn’t be surprised if the aftermarket produces a selection of railed ones.
MPX (Nick): There’s a full length top Picatinny rail for your various sights and such, but the rest of the gun leaves it up to you. The MPX ships with a proprietary handguard and rail attachment system that lets the shooter choose whether they want a sleek slick-sided shooter or a rail-festooned porcupine. That makes for a comfortable gun, with the ability to change that at the drop of a hat. The gun ships with three rail sections, and a hand stop / sling mount already on the handguards. Proprietary rail sections make me uncomfortable, but the fact that it ships with a few sections is comforting.
Scorpion (Jeremy S.): Lots of “rail estate” obviously leaves options for customization fairly open. The Scorpion in pistol form also has 4 sling attachment rings on the receiver and ships with a receiver end plate that’s slotted in various ways for a strap sling. Swappable end plates make for lots of possibilities. At current, the choices are the slotted sling plate that ships with it and the AR-15 buffer tube adapter plate, but this same mounting system is how the factory folding stock attaches and, as mentioned, I’m sure the aftermarket is going to have fun with the possibilities (edit: Manticore Arms already has a prototype telescoping stock).
No aftermarket options for pistol grips yet, but it’s a simple polymer affair so I’m sure that will come. The ability to slide the grip forwards and back to adjust for trigger reach distance is great. Charging handle side can be swapped, and there are already two different safety lever options. On the negative side, the 18×1 mm RH barrel threading isn’t something we’ve had in the U.S. so there was zero support for it. Fortunately, suppressor manufacturers have already responded with mounts and thread pitch adapters, and since 18×1 is a lot larger than 1/2×28, a gunsmith could re-thread your barrel.
Apparently if the Scorp is a big success, factory 1/2×28 versions for the U.S. market are possible. Although the Scorpion doesn’t use a standard AR-15 trigger unit, which sure would have been nice, it is a self-contained, drop-in FCG and that’s going to make aftermarket replacement a simple affair. It takes me about 2 minutes to remove the FCG from the gun.
MPX (Nick): The Scorpion has a proprietary swappable end plate, but SIG SAUER put a standard Picatinny rail on the end to let end users put whatever they want on the gun. Rock River Arms already makes a side-folding stock for a similar Picatinny mount that is on the market (which I have ordered for my MPX) and others are available as well, with SIG SAUER’s own stocks coming soon. The easily swappable handguards and barrel make the gun very appealing for tinkerers as well, allowing end users to do cool things like extend the handguards over a silencer to increase rail space while keeping the gun as compact as possible.
UPDATE: Rock River Arms has refused to sell me a stock for this gun. Their owner claims that every sale of their stock MUST be accompanied by an ATF Form 1, which is a requirement that I have never seen before from a manufacturer. So they have refused to take my money, and I’ll just go buy it elsewhere. Stay tuned.
The barrel is threaded in the standard SIG SAUER 13.5×1 metric left hand thread, which is a common threading that is already available on the market here in the US and commonly available even for AAC’s ASAP piston system. In short, not only is the MPX going to have tons of options from the factory, but the end user can change damn near everything on their existing gun and aftermarket parts are already widely available.
Scorpion (Jeremy S.): The factory iron sights on the Scorpion are pretty freaking sweet and I hope CZ-USA begins selling them separately! They’re steel, quality is top notch, the rear sight has four apertures that spin one to the next, and the front appears to accept a standard AR front sight post. The front is adjustable for elevation and the rear for windage. They mount on a standard picatinny rail. On the downside, they’re low and somewhat sleek, meaning they won’t co-witness at a normal AR height. They do co-witness with a small red dot sans riser, though, which happens to be the ideal height for optics with an SBR’d Scorp.
MPX (Nick): A set of flip-up iron sights comes on the gun from the factory along that top Picatinny rail. These all-metal sights are adjustable for elevation as well as windage, and they are very chunky to allow easy deployment and retraction. They are designed for standard AR-15 heights, meaning an SBR’ed MPX will see the sights perfectly aligned with your eye.
OtherCrap Included in the Box:
Scorpion (Jeremy S.): bore snake for cleaning, two magazines, sight adjustment tool, manual & warranty info, accuracy target, gun lock.
MPX (Nick): Three rail sections. A full mil-spec cleaning kit. A bottle of lubricating oil. A QD single point sling. Once 30-round magazine. And a gun lock. Oh, and “the box” in this case is a proper polymer gun case with a foam insert precision cut to keep the MPX securely in place. Its actually a very useful gun case, and looks great to boot.
Scorpion (Jeremy S.): 5-year limited warranty. (All CZ-USA firearms are warranted to be free from defects in material and workmanship for one (1) year on wooden parts and surface treatment and five (5) years on other parts to the original purchaser.)
MPX (Nick): LIFETIME limited warranty from SIG SAUER. If your gun has any manufacturing defects they will happily fix it for you. The warranty only extends to the lifetime of the original purchaser, so make sure your 18 year old son buys the gun and not your grandfather.
Scorpion (Jeremy S.): MSRP $849
MPX (Nick): MSRP $1,648 with brace, $1,378 without.