Cosaint Arms COS21 Commander .45 ACP Double-Stack, 4.25 in Bull Barrel, 14+1, Rail, Custom Upgrades
This Cosaint Arms COS21 Commander is a customized, double-stack .45 ACP built on a 1911/2011-pattern platform. It features a bushingless bull barrel, integral accessory rail, and a matte gray slide and frame. Upgrades include a Gen 1 STI treebark grip module, Nighthawk gunsmith-fit internals, a Red Dirt flat trigger, and a Wilson Combat single-sided thumb safety. It ships with six 14-round magazines and a Streamlight TLR-1 HL weapon light.
Condition
Overall Condition: Good condition, showing some signs of prior use and handling.
Bore Overall Condition: Good - Clean, well-maintained, minor wear marks.
Bore Rifling: Good Rifling - Intact, well-defined lands and grooves.
Specific Condition Notes: This firearm is in solid shape. There are some scratches and blemishes present.
What’s Included
- Cosaint Arms factory hard case
- User manual
- Six 14-round magazines (MBX-branded basepads installed)
- Streamlight TLR-1 HL weapon light
- OEM polymer grip frame (spare grip module)
- Original dual thumb safeties
The COS21 Commander pairs a 4.25 inch Commander-length slide with a double-stack frame for a 14+1 capacity in .45 ACP. The slide is marked "COS21" and finished matte gray, with forward and rear cocking serrations and a flat-top profile with bevels. The dust cover carries an integral Picatinny-style accessory rail, and the frame is finished to match.
Its bushingless bull barrel has a polished chamber visible through the ejection port, with the barrel hood marked "CAL. 45 ACP." Sights are dovetailed iron units with a red fiber-optic front and a plain black rear for a clear, fast sight picture.
This pistol is thoughtfully upgraded: a Gen 1 STI treebark-textured modular grip improves control, while Nighthawk gunsmith-fit internals and a Red Dirt flat-faced trigger with lightening windows refine the action. A Wilson Combat single-sided left thumb safety is installed, complemented by a beavertail grip safety with memory bump and a skeletonized rowel-style hammer. A flared bolt-on magwell, finished to match the frame, speeds reloads.
The pistol uses a double-stack 2011-pattern magazine interface. Included magazines are fitted with MBX-branded basepads. The frame is marked "COSAINT ARMS • EAST FLAT ROCK, NC," and the pistol is made in the United States.
Included Streamlight TLR-1 HL weapon light: 1,000 lumens, 1.50-hour runtime, 283-meter beam distance, 20,000 max candela, powered by two CR123A lithium batteries. It measures 3.39 inches in length, weighs 4.32 ounces, and is black.