Steyr AUG/A3 and MSAR STG-556

I recently reviewed the new U.S. version of the Steyr AUG/A3.  At the time I noted that Microtech Small Arms Research (MSAR), which has spent several years rolling out its “STG-556” AUG clone, would probably retain a pricing and innovation edge over Steyr.  During the recession MSAR cut its wholesale price from above $1400 to $1050.  Then, in just the last few weeks, MSAR dumped their entire inventory on distributors at even lower rates, allegedly because they are moving their operations from Bedford, Pennsylvania to Raleigh, North Carolina.

Since I was already thinking about getting another receiver or barrel, I couldn’t pass up an opportunity to get an entire bullpup carbine for under $1100.  Following are observations on the fourth-generation STG-556 I purchased, shown here below my Steyr AUG/A3 USA.

I was struck by a number of small but clever improvements MSAR has made to the AUG design:

  • The MSAR 16″ barrel uses 1:8 rifling, which is sufficient to stabilize up to 77gr bullets.  (The AUG only comes with 1:9 twist, which is marginal for bullets over 70gr.)
  • The MSAR is more than half a pound lighter than the AUG/A3.
  • The MSAR has quick-detach sling loops on both the receiver and the stock pin.  (In contrast, the AUG’s front sling loop is held in by a coil pin so it cannot be easily removed when not in use.  Its rear loop can be switched from side to side by removing the entire stock pin, but cannot be completely removed.)
  • The MSAR stock has two QD sling loop attachment points molded into the stock, underneath the pistol grip and under the toe.
  • The MSAR trigger pack actually locks into the stock.  You have to press the bolt catch to release it.  (The AUG’s trigger pack just falls out.)

The MSAR beats the Steyr not only on price but also with these design enhancements.  The only two things the AUG has going for it are (1) the support and reputation of Steyr-Mannlicher, and (2) the fact that it has met the production and performance standards of many professional militaries for many decades.

Other observations:

  • A new MSAR is tighter than a new AUG in a several dimensions: You actually need the help of the recoil spring to get the receiver to pop out of the stock during disassembly.  And magazines do not drop free when released unless nearly fully loaded.
  • The MSAR bolt locks open on an empty magazine, after which it can only be closed using the bolt catch just above the magazine release.  In contrast, the AUG bolt can also be released using the slide-cocking handle.
  • The Gen-4 MSAR has no forward assist.  The AUG’s slide-cocking handle can be used as a forward assist.
  • Sadly, like the AUG, the standard STG-556 barrels use metric muzzle threads, so you’ll have to buy an adapter to use your American suppressors.

Important notes when purchasing an STG:

  1. MSAR’s fourth generation starts with serial number 6500.  MSAR has manufactured at least five thousand Gen4 STG-556 guns.
  2. Earlier STG-556 versions have a Stoner-style Forward Assist (“FA”) and some compatibility problems.  Therefore I would avoid serial numbers lower than 6500.
  3. Don’t confuse the STG-556 with MSAR’s STG-E4.  The E4 is a Gen4 variant compatible with AR-15 magazines — quite like the Steyr NATO conversion I described previously.  It comes with many more rail mounting positions and runs at least another $250.
  4. The Gen4 STG-556 works with AUG magazines.  (It also appears to work with Steyr’s NATO conversion kit, although I only confirmed that its receiver fits in mine; I haven’t test fired it.)
  5. It ships from the factory with 5 MSAR magazines.
  6. MSAR STG-556 magazines do not work with AUGs without some extra machining.

12 thoughts on “MSAR STG-556 vs AUG

  1. Pingback: EmptorMaven » Blog Archive » Steyr AUG/A3 USA

  2. Tristan

    I enjoyed reading this reviewe and comparison, and I would like to ask you a few questions. I am currently in the market for an aug, so I’m either going to get the A3 or the MSAR Gen4. Which would you recommend after owning both now for awhile?

    I really like the A3 for it’s support and use of original Steyr parts. However I like the MSAR 556 for it’s price and the rail being raised up and shorter. I have looked and it has been hard for me to find a good review of both.

    Have you had any issues with the MSAR? How many rounds have you put through it? Any of the design elements on the MSAR you have come to like or dislike?

    Basically I need to you talk me into buying the MSAR ot buying the A3 🙂

    Thanks for your time.

  3. federalist

    I haven’t had the chance to put many rounds through either, but a single gun isn’t much of a sample size anyway. Both models are part of production runs in the thousands of units and are backed by companies with good customer service reputations.

    Given the current MSAR price I would definitely buy more of those instead of the A3. Even if they were priced identically I would probably still opt for the MSAR just because of the various bonus features I cited above.

  4. Lady Mondegreen

    My MSAR only came with one 10 round magazine and I haven’t been able to jind any more. The place where I bought mine did not even offer any extra magazines and no longer sells the MSAR. Where can I find the appropriate magazine for this piece?

  5. Pingback: EmptorMaven » Blog Archive » AUG and MSAR Trigger Improvements

  6. Pingback: EmptorMaven » Blog Archive » RAT WORX Hybrid Trigger Mod: The Best AUG Trigger

  7. Pingback: EmptorMaven » Blog Archive » CQB Rifle Optics

  8. Ralph

    I know this post is very old, but I was curious if you ever tested Steyr’s NATO conversion kit in your STG-556. I heard the bolt release wouldn’t work, but I wouldn’t mind that as long as the kit was safe to shoot.

  9. federalist

    It was six years ago, but I believe I did assemble my STG-556 into the Steyr NATO conversion kit and it function checked. I would expect it to work, even if it takes a little sanding to fit. And using the charging handle to release the bolt it easier on these guns anyway.

  10. Ralph

    Thanks for the prompt reply. The reason I asked about the bolt release was because if I used the charging handle while the bolt (and charging rod) was locked to the rear, the handle would always snag initially due to some pin. I understand the pin is there for the same purpose as the latch on the AR-15 charging handle (to not have the CH move around freely), but I would end up scuffing my hands pulling back on the CH. I didn’t know if there was a way to make that pull-back smoother.

  11. USA1791A1

    I know this is an ancient post, but I recently took a chance and bought one that showed up at my local gun shop………so as a new owner of a used MSAR XM17-E4, I couldn’t help but chime in………l am very satisfied with my purchase! Accurate, reliable and easy to clean/maintain. Parts will be a challenge, since Microtech no longer produces this rifle (and what a shame that fact is) however a few original Steyr AUG parts do fit, and Ratworx is producing some parts as well. A recent talk with them indicated that more parts for the XM17-E4 are on the horizon. Have located some parts on various auction sites as well. I cannot vouch for earlier models…..I hear there were some early teething problems……but I can say MY particular weapon, which is a serial number above 10,000, has been VERY reliable……..shot it today with out one issue. I don’t know if anyone out there is still looking for or considering one of these rifles but , but just for what its worth…………


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