The Geissele ICM 15-round magazine is a purpose-built rifle magazine developed for shooters using 6mm ARC, 22 ARC, or 6.5 Grendel cartridges in a compatible mil-spec AR-15 lower. Rather than adapting a conventional 5.56 magazine body to cartridges with different dimensions and feeding requirements, Geissele designed the Intermediate Cartridge Magazine with cartridge-specific internal geometry, optimized feed lips, and an anti-tilt 6mm ARC follower. This configuration supports controlled cartridge presentation and dependable feeding while retaining compatibility with the familiar AR-15 magazine well. The 15-round model measures 5 inches in overall length, providing useful ammunition capacity in a compact format that is convenient for bench shooting, hunting, range use, and field carry. Its body and mating components are made from 410 stainless steel and joined with laser-welded, one-piece construction for strength and consistent geometry. A black nitride coating supplies the magazine's subdued black finish while helping protect its steel surfaces against corrosion and routine handling wear. Inside, a stainless steel square spring maintains pressure on the anti-tilt follower as cartridges are loaded and cycled. The feed lips are shaped around the supported intermediate cartridges rather than general-purpose 5.56 ammunition, helping the magazine manage their wider case dimensions and feeding angle. Ribbed exterior panels reinforce the steel body and provide practical gripping surfaces during loading, removal, or magazine changes. The metal floorplate closes the bottom of the body and allows the magazine to maintain a traditional, streamlined profile. Made in the United States, this Geissele ICM is the black 15-round configuration and should be paired only with a firearm properly chambered and configured for one of its specified cartridges. Always confirm firearm compatibility and observe applicable magazine-capacity laws before purchase or use.Specifications and Features: 15-round capacity Optimized for 6mm ARC, 22 ARC, and 6.5 Grendel cartridges 5-inch overall length Laser-welded one-piece construction 410 stainless steel body and mating components Black nitride corrosion-resistant coating Stainless steel square spring Cartridge-optimized feed lips Anti-tilt 6mm ARC follower Compatible with mil-spec AR-15 lowers Made in the USA Brand: Geissele Series: ICM Product Type: Rifle Magazine Manufacturer Part Number: 05-3231 UPC: 810081135825