Detonics Combat Master Mk I .45 ACP Compact 1911 — Early Seattle Carbon-Steel Variant, 3.5" Bull Barrel
This Detonics Combat Master Mk I is an early Seattle-produced, carbon-steel example distinguished by its scarce “C” serial prefix. Built between 1979 and 1981, it combines a compact 3.5-inch stainless bull barrel with the company’s patented dual/tri-coil captive recoil spring and the deletion of the traditional 1911 grip safety. Collectors prize these limited-run carbon-steel pistols for their short production window—roughly 18 months—and their role in popularizing the modern concealed-carry 1911 platform.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Condition: Excellent – Clean, mirror finish, no signs of wear.
Rifling Condition: Excellent – Sharp lands and grooves.
Specific Condition Notes: Minor, superficial scratches and small blemishes are present on the matte-blue finish. The bore remains bright and shiny.
What’s Included
- Detonics Combat Master Mk I pistol
- 1 × 6-round stainless single-stack magazine with witness holes
Seattle-made Combat Masters like this one represent the first generation of Detonics compact 1911s. The carbon-steel frame and slide, finished in matte blue, were produced for only a short period before the company shifted to stainless construction, making this variant uncommon.
The 3.5-inch, bushing-less stainless bull barrel enhances lock-up and reduces felt recoil. Detonics paired it with a patented dual/tri-coil captive recoil spring system to ensure reliable cycling despite the shortened slide travel—a notable engineering solution for compact .45 ACP pistols of the era.
True to Mk I form, the pistol omits the traditional grip safety, streamlining the grip profile. A spur hammer, manual thumb safety, and vertical rear slide serrations complete the operating controls.
Fixed sights include a forward-set rear square-notch and a low-profile blade front, a signature Detonics layout designed to clear the hammer spur while shortening the sight radius for easier concealment.
With approximately 17,000 Combat Masters produced during the original Seattle run—and far fewer in carbon-steel—this well-preserved example offers both shootability and collectibility for enthusiasts of compact 1911 history.