This magazine is for Rock Island's 22 TCM Rifle and is constructed of metal with a blued finish.The Rock Island Armory 22 TCM Bolt Action Magazine is a standard factory replacement magazine. This magazine is for the new 22 TCM Bolt Action Rifle models chambered in 22 TCM and holds 5 rounds of ammunition. It is made of steel and is made to Armscor/Rock Island Armory specifications and tolerances, using the same manufacturing and materials as the original equipment magazines, ensuring perfect fit and operation.