Stainless steel construction Corrosion-resistant finish High-strength steel spring Polymer follower Maximize your Thompson submachine gun's firepower potential with the Auto OrdnanceA(R) Thompson 1927 A1 .45 ACP 100-Round Drum Magazine from GunMag Warehouse. This ultrareliable SMG magazine features durable stainless steel construction with a corrosion-resistant blued finish for unparalleled strength, lasting corrosion, and shock resistance you can depend on. Featuring a unique rotary design with a high-strength steel spring and a polymer follower, this ultrareliable factory magazine offers smooth, jam-free operation without breaking the bank. Founded by John T. Thompson as the company that would go on to launch the historic Thompson submachine gun, Auto Ordnance stays true to the heritage of America's most iconic weapons while continually refining and improving its designs. Will NOT fit firearms made in West Hurley, NY, or before 1990. What are you waiting for? Pick up a new high-capacity drum magazine for your Thompson submachine gun today! Order now.