The Sig Sauer MPX Competition is a 9mm semi-automatic rifle with a 16-inch barrel, 35-round capacity, and a gas piston operating system. The Competition variant is specifically set up for PCC competition with a Timney single stage trigger and Magpul SL-K folding stock. 
 

Key Specifications 

• UPC: 798681666751 
• Caliber: 9MM LUGER (9X19 PARA) 
• Action: Semi-Automatic 
• Capacity: 35 Rounds 
• Barrel Length: 16 inches 
• Weight: 6.63 lbs. 
• Finish: Black 
   

Detailed Features 

The gas piston operating system keeps the action cleaner than a blowback design, which matters for 9mm PCCs that see high round counts in competition. The Timney single stage trigger is installed at the factory and has the consistent, light pull that competition shooters want without needing aftermarket work. 
 
The Magpul SL-K stock adjusts to length of pull and folds for storage or transport. The aluminum M-Lok handguard keeps weight low and accommodates lights, foregrips, and other accessories without tools. The MPX uses proprietary SIG magazines, which is a compatibility consideration for buyers who may already have a supply of a different 9mm magazine.

The SIG MPX Competition is discussed almost exclusively in PCC competition contexts, and most owners bought it with that intent. Accuracy and trigger quality are the most praised attributes -- the factory Timney trigger is specifically mentioned as one of the best factory triggers available in a PCC, which saves competitors money on aftermarket upgrades.

Recoil management from the gas piston system is well-regarded. Owners compare it favorably to blowback-operated PCCs and credit the smoother impulse for faster target transitions in stages.

Build quality and Sig's fit and finish get consistent positive mentions. The rifle handles reliably across various 9mm loads.

The 35-round capacity is practical for competition stage design and owners appreciate it.

The SIG proprietary magazine system comes up regularly as a practical limitation. Buyers who already own Glock or CZ magazines for their pistols have to maintain a separate magazine ecosystem. Price is consistently described as high but accepted as the cost of a competition-ready package. SIG customer support feedback is mixed -- some owners report good experiences, others have faced delays.

Customization discussions focus primarily on optics, as the rifle is otherwise competition-ready from the factory.

I’ve been waiting to get my hands on the SIG Sauer MPX for ages, and it was totally worth it. Right off the bat, this thing just feels perfect. It’s built for competition, especially for USPSA PCC, but honestly, it's so much more. I’m a sucker for a smooth-shooting gun, and the MPX’s short-stroke gas piston system makes it the softest-recoiling PCC I’ve ever shot. The ambidextrous controls are great, and I love how easy it is to swap out parts like the handguard and barrel. Plus, the flat-faced trigger is a game-changer—quick, clean, and just plain fun to shoot. I ran about 200 rounds through it, and every shot felt like butter. It’s crazy accurate and barely moves between shots, so follow-ups are fast and tight. After trying out all kinds of PCCs, this one takes the crown. I’ve been after this gun for so long, and I’m stoked it lived up to the hype. It’s definitely my new favorite.