KCI USA .40 S&W 31 Round Extended Magazine, Steel Reinforced Polymer Construction, Black

KCI USA .40 S&W 31-Round Extended Magazine, Steel Reinforced Polymer, Black

The KCI USA .40 S&W extended magazine is a 31-round Glock pattern design for Glock pattern .40 S&W pistols. The magazine body is polymer with a hardened steel insert for reinforcement, a polymer follower, and an extended polymer base plate in matte black. Witness holes are present along the body and the magazine is drop-free compatible.

Key Features

• 31-round capacity, extended
• .40 S&W caliber
• Glock pattern compatibility
• Polymer body with hardened steel insert
• Polymer follower
• Extended polymer base plate, matte black
• Witness holes
• Drop-free design

Perfect For

• Glock pattern .40 S&W pistol owners sourcing a 31-round extended magazine with steel-reinforced polymer construction
• Shooters who want a high-capacity extended magazine for range use or competition with their Glock pattern .40 S&W platform
• .40 S&W builders completing a Glock pattern pistol build who need a drop-free extended magazine included without sourcing it separately

Construction and Design

The magazine body is polymer with a hardened steel insert that reinforces the feed lips and body structure along the areas that experience the most stress during loading and cycling. The extended capacity of 31 rounds requires a longer body and extended base plate compared to a standard capacity Glock pattern .40 S&W magazine. The polymer follower guides the top round into a consistent feed position as the magazine empties. Witness holes along the body allow round count verification without removing the magazine from the pistol. The drop-free design allows the magazine to fall clear of the mag well under its own weight when released. The extended polymer base plate in matte black provides additional grip surface at the base of the magazine for positive extraction during a reload.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. Verify local and state laws regarding magazine capacity before purchasing.