SIG MCX Rattler Ultra Compact Assault Rifle

Manufacturer SIG Sauer brought along their brand new MCX Rattler ultra compact 5.56mm and .300 Blackout assault rifle/carbine to the 2017 Association of the United States Army annual meeting. The Rattler is an ambitious design intended to bring a reliable extremely short barreled AR-type rifle to the military and civilian market. Historically, designing very short barreled gas operated rifles that function well has been a serious challenge, so the Rattler’s designers had a tall order to fill.
Around the Rattler, the SIG booth was very crowded with conference attendees wanting to see the new shortie. Sadly, the booth was also not well lit, and I did not get many photos of high quality. Therefore, at the end of this article I have also embedded some of SIG’s press photos of the Rattler to balance it out.
The SIG MCX Rattler, above an MPX SBR. Note that the Rattler is little, if any, longer than its pistol-caliber stablemate.

SIG had a helpful display of barrels and handguards for the Rattler. Top right, we see the 5.5″ barrel, below that a 7.5″ barrel. An extended Rattler handguard is seen to the left.

My impressions of the Rattler were generally positive, with some caveats. The good first: The rifle is laid out with all the creature comforts one expects of a modern premium AR-type gun, including ambidextrous mag catches. Generally, speaking, the rifle was comfortable to shoulder for such a small gun, without being too cramped. The odd-looking pistol grip was reasonably comfortable, as well. However, I felt as though the stock was not the best design. It uses an unusually short toe which forces the shooter to bring the gun deep into their shoulder pocket, something I find uncomfortable and unnatural. Given where the toe sits alongside the magazine well when it is folded, I am not sure why SIG decided not to simply make it an inch or more longer.