Below is my review of the Microtech Small Arms Research (MSAR) STG-556:
The first (rather obvious) thing to note is that the MSAR STG-556 is bullpup, meaning that the action and magazine are located behind the trigger. Compared to traditional rifles, which place the action and magazine in front of the trigger, a bullpup is able to make use of what would otherwise be wasted space in the stock. The net result is a rifle that has a shorter overall length, for any given barrel length. In the case of the MSAR STG-556, it is shorter than my AR-15, even when the AR-15’s stock is fully collapsed – yet both rifles have a 16″ barrel. This can be especially beneficial in close quarters self defense use, although a rifle is not my first choice when it comes to home defense.
The MSAR STG-556 is made in the USA by MSAR, a subsidiary of Microtech (the excellent and expensive knife manufacturer), and is chambered for .223/5.56mm. The semiautomatic STG-556 is based upon the Steyr AUG, which is a fully automatic bullpup rifle from Austria that has seen service with many countries. There are some other differences between the Steyr AUG and the STG-556, making magazines and some other parts incompatible. The STG-556 also has a forward assist, which the Steyr AUG lacks.
Models are available with 14″, 16″, and 20″ barrels. A flash suppressor/muzzle compensator or sound suppressor is also available from the factory. The 14″ barrel and sound suppressors are National Firearms Act regulated, so for most people the realistic options are a 16″ or 20″ barrel, with a flash suppressor. I opted for the 16″ barrel and a combination flash suppressor/muzzle compensator.
As far as sighting options, the STG-556 comes with either a 1.5x scope, or a 9″ accessory rail to which the optics of one’s choice can be mounted. I opted for the accessory rail and attached a red dot scope.
In terms of magazines, MSAR offers 10, 20, 30, and 42 round versions. The magazines are made of translucent plastic, and feel quite sturdy. They sort of remind me of the Magpul PMAG. The “E4” version of the STG-556 uses standard AR-15/M-16 magazines, rather than the proprietary magazines from MSAR.
The MSAR STG-556 is a well built rifle that feels (and is) on the expensive side. I’ve found each part to be well manufactured, with attention paid to the fit and finish. Disassembly and reassembly is easy, requiring no tools and not that much effort, thanks to the attention to detail that MSAR apparently paid during the manufacturing process.
It is worth nothing that just about every part on this rifle that can be made of polymers is made of polymers – including even the hammer. I like this, since polymer components are rust proof and corrosion resistant. However those who prefer traditional rifles likely won’t appreciate this any more than they appreciate the bullpup design.
The biggest potential problem area with bullpups is the trigger. Because the trigger is forward of and separated from the hammer mechanism, there must be a mechanical linkage connecting the two. This linkage can result in a trigger that feels mushy or requires excessive force to fire. Having fired the MSAR STG-556, I can say that its trigger is not bad. The trigger on my AR-15 is clearly crisper and requires less force, but I’m not at all dissatisfied with the STG-556’s trigger.
Out of every rifle I’ve held, I would say that the MSAR STG-556 is the second most comfortable, being narrowly beaten out by the Beretta CX4 Storm. The stock fits nicely against my shoulder, and the pistol grip and trigger are comfortable – with or without winter gloves. In particular, I like the vertical forward grip. My fiancé agreed, and basically said that she has no desire to every fire my AR-15 again again, given how much more she likes this rifle.
The controls are well placed, and I like how the charging handle is on the front right side, rather than at the rear like on the AR-15.
Left handed shooters will be happy to note that the MSAR STG-556 can be easily converted to eject from the left side. All that is required is a different bolt, and the swapping of a plastic ejector port cover from the left to right side of the rifle.
The MSAR STG-556 uses a gas piston system, which avoids some of the chamber fouling issues that historically have been attributed to reliability problems within the AR-15/M-16 family. I can say that my STG-556 seems to be quite reliable, which I would expect given the decades-long track record of the Steyr AUG, whose design the SGT-556 is based upon. That said, as always, I still prefer a pump action shotgun when it comes to home defense purposes.
To the extent that I can test accuracy with a red dot scope mounted on my MSAR STG-556, I would say this is a nicely accurate rifle. I haven’t fired it at targets beyond 100 yards, but at 100 yards I can tell that my skill level (and the fact that I was firing it at a cold outdoor range with cold hands) was the limiting factor.
The MSAR STG-556 is now my new favorite rifle, having taken that crown from my my Rock River Arms AR-15. I love the bullpup design, and the extensive use of polymers in the construction of this rifle. I find it to be accurate, reliable, well designed, and a joy to shoot. The short overall length is especially nice for those concerned about use in close quarters, such as self defense within a smaller home. Those considering a rifle in .223 should give thought to the STG-556.
Note: I promised a couple people some pictures and video clips of this rifle. The fact that it was 25 degrees at the outdoor range meant that I didn’t spend a minute longer than necessary to fire the rifle then retreat to my warm car. Rest assured, I’ll take some pictures and video clips once it is a bit warmer outside.