The ProMag COL-21 is a low-profile, 5-round replacement magazine designed for AR-15 rifles chambered in .223 Rem/5.56 NATO. It uses a heat-treated steel body and an injection-molded follower to deliver reliable feeding in a flush-fit configuration. The magazine spring is formed from chrome-silicone wire, and at least one source identifies this product as made in the USA.
Key Specifications
- Holds 5 rounds.
- Chamber compatibility: .223 Rem/5.56 NATO.
- Designed for the AR-15 platform.
- Body constructed from heat-treated steel.
- Fitting style is flush-fit.
- Includes an injection-molded follower.
- Uses a mag spring formed from chrome-silicone wire.
- Model designation: COL-21 (Standard).
- Manufacturer brand: ProMag.
- At least one source lists origin as Made in the USA.
This compact, low-profile magazine is a practical spare or replacement for range use and field carry where a flush-fit profile is preferred. Its steel construction and chrome-silicone spring are intended to provide consistent feeding and service life under routine use.
This description was generated with AI and may contain errors. Verify specifications and legal restrictions with the manufacturer before purchase. Provided “as-is” without warranties or guarantees.
