The Sig Sauer MPX Copperhead K is a semi-automatic pistol in 9mm Luger (9x19 Para) with a 4.5-inch barrel, 20+1 capacity, and overall length of 14.50 inches. It weighs 4.5 lbs. The receiver is black anodized aluminum. Ambidextrous safety, black polymer grips, and M-Lok handguards. The sights are optic-ready. A Timney single-stage trigger is fitted. 
 

Key Specifications 

• Brand: Sig Sauer 
• Model: MPX Copperhead K 
• Caliber: 9mm Luger (9x19 Para) 
• Barrel Length: 4.5 inches 
• Capacity: 20+1 rounds 
• Action Type: Semi-Automatic 
• Weight: 4.5 lbs. 
• Finish: Black Anodized 
• Safety Style: Ambidextrous  
• Grips Material: Black Polymer  
• Sights Type: Optic Ready 
   

Detailed Features: 

The 4.5-inch barrel keeps the Copperhead K compact at 14.50 inches overall. The Timney trigger has a short reset and crisp break, which is a real upgrade over mil-spec triggers. M-Lok handguards make accessory attachment easy. The ambidextrous safety and controls work for either hand. At 4.5 lbs it's light for what it is. Optic-ready receiver accepts standard mounts.

The MPX Copperhead K draws strong reviews from shooters who know what they're buying. Accuracy is consistently praised. The quality of the optics-ready receiver and the Timney trigger combination gives it real precision for a pistol-format firearm. Build quality matches Sig's reputation, and the compactness at 4.5 lbs and 14.50 inches overall is genuinely useful in tight spaces.

Price is the most common friction point. The Copperhead K is at the expensive end of its category, and that generates comparison discussions with cheaper options. Some users note recoil as snappier than expected for a heavier-framed gun, which matters more for new shooters. Accessory and part sourcing for specific Copperhead configurations gets mentioned occasionally as a limiting factor.