TFB Review: SIG Sauer MCX Rattler – 1 Year Later

    Most of you guys will probably understand when I say I have a list of guns I’d love to own someday, but it’s always followed up by “if I win the lottery.” I have a few of those guns on my list but when I saw the new MCX Rattler from SIG Sauer, I felt like it was something fresh in the market and that was exciting to me. I checked it out at SHOT Show and NRA’s annual meeting last year. I always thought it was a useful system and again I was interested in shooting it. Thankfully, I found one and had the opportunity to buy it, so I did! Let’s get into what I think about it one year later.


    First of all, the gun packs a huge punch for a very small package. The overall length is around 16 inches from muzzle to the end of the brace. It’s chambered in 300 Blackout as well with a 5.5-inch barrel. The gun weighs just over 5 pounds without optics. It’s a solid little gun built like a tank, but it’s not a bad weight at all. I love how SIG always puts QD mounting points in all of their rifles and pistols. The mounts made it really easy to put on a single point sling and run with it. I set my gun up with a Trijicon RMR on an Anvl Ukon mount.

    The Anvl Ukon mount has iron sights system built right into the mount so there’s no need for backup irons on the gun. I thought the initial concept was odd but once I started using it on a PDW system, honestly, I think there isn’t a better option on the market now. I was initially interested in this optics setup because there have been a number of special forces teams around the world who use the MCX Rattler with a Trijicon RMR on an Ukon mount. It’s easy to see why they went with this setup! I threw a Surefire M300 Mini Scout weapon light with a Phase 5 single Point sling and called it good.

    Range Days

    So far I’ve put around 3,700 rounds through the MCX Rattler, and it has been 100% reliable. I’m averaging 1.5” groups at 100 yards. It doesn’t sound overly impressive until you think about the fact it only has a 5.5-inch barrel. The gun is an absolute blast to shoot and the recoil is extremely manageable. I was surprised how easy it is to keep on target during drills or transition shooting and even though it’s a very small package the gun doesn’t beat you up with muzzle blast or huge fireballs. My gun came with SIG’s three-prong flash hider and it does a good job minimizing muzzle blast. 

     Some Things I Changed Over Time 

    There are a few things you have to get used to when it comes to the MCX Rattler though. The first thing I’m not a huge fan of the small charging handle on the gun. I totally understand it is a PDW weapon so everything is streamlined and made to be as low profile as possible. The charging handle is very compact which is great for pulling out of a concealed carry bag. The downside to this is it’s pretty tough to use when charging the gun. I changed mags a few times at the range and by the end of the day my knuckles were raw, but it wasn’t a deal breaker.

    I picked up a Geissele Super X charging handle for the Rattler which fixed the issue. The only other thing I switched out on the gun was the collapsible pistol brace. The brace was adjustable which is a plus but I preferred a side folding brace that is easy to deploy. The collapsible stock was really well built, but to deploy it quickly you need two hands. The side folding brace only takes one hand to quickly deploy it. This is my personal preference, but again it’s a very small issue on an otherwise fantastic firearm. Both of these issues are easily fixable with a charging handle and SB Tactical Side Folding brace.  

    Overall Thoughts  

    When I first picked up the MCX Rattler, I was really worried it wouldn’t live up to my high expectations. After owning and carrying it, I’m happy to say it has met if not exceeded my expectations. The gun just runs and has a massive amount of firepower in a tiny package. I love the fact I can throw it in a single strap bag and carry the Rattler around without any issues or it seeming cumbersome.

    I will probably be purchasing a new Vertx sling bag for the Rattler and will write up what I think about it. Over the next 6 months, I plan on traveling so it’ll be traveling with me. I plan on keeping you guys updated with my experiences with the Rattler but after 1 year, it’s been fantastic. As always, if you guys have any questions or comments please feel free to email me. Also, be sure to follow my Instagram account, and as always stay safe out there.

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    I’m an avid shooter and love educating whether it’s at my job or in the shooting community. I’m an average joe that really loves talking with other people about firearms and other passions
    .I’m active on Instagram on @fridgeoperator @just_pistols @thedailyrifle.