ProMag RM40FDE Standard AR-15 5.56x45mm NATO 40rd Flat Dark Earth Polymer Detachable

The ProMag RM40FDE is a 40-round detachable AR-15 magazine from ProMag's Rollermag line, built to keep a high round count on tap for range work, training, and high-volume shooting sessions. It is designed to feed both 5.56x45mm NATO and .223 Remington, so it drops right into any standard AR-pattern rifle or carbine lower without modification.

The magazine body is molded from a proprietary DuPont Zytel polymer that keeps weight down and shrugs off rough handling, finished in a low-glare Flat Dark Earth that pairs cleanly with FDE rifles, furniture, and accessories. Inside, ProMag's patented anti-tilt roller follower and a steel wire magazine spring work together to keep each round aligned, promoting reliable feeding from the top of the stack all the way down to the last round.

Engineered as a direct replacement or spare magazine for any standard AR-15, the RM40FDE seats and drops free from the mag well without fuss. The combination of 40-round capacity, durable polymer construction, and a roller follower design makes this a go-to choice for shooters who want to spend less time reloading and more time behind the rifle. Made in the USA by ProMag.