Figured I'd post this here, as Surefire seems to produce these in limited runs, and I don't see them crop up that often.

Just got of the phone with Surefire and ordered one MB556K-AUG, the discontinued AUG Muzzle Brake (non-SOCOM).  They apparently don't have too many left sitting around.

Wow! How much was it? What is the difference between this one and the SOCOM?

The brake itself is $149.99.  

The legacy brakes are pretty similar to the SOCOM, just a different adapter mechanism for the suppressor.  As far as their compensating abilities, I'd say they exactly the same.

Legacy:
http://www.surefire.com/mb556k-sb-muzzle-brake-adapter.html

SOCOM:
http://www.surefire.com/sfmb-556-1-2-28.html

I said 'fuck it' and just used the regular SOCOM brake with the Ratworx adapter. Actually worked out well because the adapter pushed it far out enough on the 18" barrel to clear the CQC forend.

18" barrel or Original CQC 16" barrel ???

18" barrel, thanks to PJs black friday sale.

It'd be nice if Steyr just had the US made barrels for the US market spec'd with a 1/2x28 thread.

Exactly

Yeah, but then there would have been all the "It's not AUTH-entic!" and "Thanks for the anti-freedom flash hider!" cries.  You can't win for losing in that game.

Richard

Were there any fit issues with the 18" barrel with the Surefire Muzzle Brake + SOCOM556-RC Suppressor and the CQC Rail system?   How much clearance between the CQC Rail and the Suppressor?  I'm trying to make sure the 18" barrel is long enough before I buy one.  Thanks...

Pete

I'm using a SOCOM 7.62 Mini suppressor actually. But no, no fit issues, the brake isn't big enough to cause any issues with taking the CQC forend on and off.

Only initial issue was that with hot-loaded ammo (Freedom Munitions new mfg 62gr), had about four stovepipes within four mags when suppressed, and ejection when suppressed was going roughly to the 1 o'clock position. I discussed the matter with an Austrian military guy on lightfighter, and he told me that on the current military models, the gas regulator no longer has an adverse setting. It goes normal, and then suppressed. The suppressed position is where the adverse setting normally is on the gas regulator, and is actually a larger hole than the normal setting. Sounds contradictory compared to how adjustable AR gas blocks are set up, I know. The idea is that that way, more gas gets vented out the side rather than being vented back into the action and overgassing it. He measured suppressed port for me and it came out to .101. I drilled mine out to .107 (only drill bit of that general size that was around the house) and test fired it yesterday. Ran five mags through at a fairly fast pace and had no issues. Having that suppressed setting pushed the ejection pattern back to 2 o'clock when suppressed, and no malfunctions at all.

I call it the Suppressable Marksman AUG. Or for short, the SMAUG.

Arrived last week, and just got it installed.  Holy cow was the factory flash hider a bear to get off.

Can I ask what back up sights you are using there?

Those are Magpul MBUS Pros.