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.