The Heckler & Koch Mark 23 is a semi-automatic pistol chambered in .45 ACP with a 5.87-inch threaded barrel. It has an OD Green frame paired with a black slide and holds 12 rounds. Sights are 3-dot style and the threaded barrel accepts standard suppressor-ready muzzle devices. 
 

Key Specifications 

• Brand: Heckler & Koch 
• Model: Mark 23 
• Caliber: .45 ACP 
• Action: Semi Auto 
• Capacity: 12+1 
• Barrel Length: 5.87" 
• Color/Finish: OD Green / Black 
   

Detailed Features 

• 5.87-inch threaded barrel 
• OD Green frame with black slide 
• 12-round magazine capacity 
• 3-dot sight system 
• Double-action trigger mechanism

The HK Mark 23 has a devoted following among collectors and those who want a large-format .45 ACP pistol with genuine military heritage. Owners consistently cite the build quality as exceptional, with tight tolerances and a finish that holds up under heavy use. The OD Green and black two-tone is the classic configuration that most buyers seek out.

The 5.87-inch threaded barrel and overall size mean this is not a carry pistol for most people. Owners use it primarily at the range or as a safe queen, and a few run it suppressed given the threaded barrel. The double-action trigger is smooth by .45 ACP standards, though the long reset is a point of discussion among competitive shooters.

At its price point the Mark 23 is a premium purchase that does not apologize for its cost. Buyers who understand what they are getting accept the trade-offs. Those who want a compact carry .45 typically look elsewhere, but for the full-size platform the Mark 23 remains a benchmark.