A single-use magazine for a firearm. A disposable magazine for a firearm comprises a first portion having a plurality of female locking members and a first segment of a spring retainer. The magazine includes a second portion having a plurality of male locking members and second segment of the spring retainer. The magazine comprises an opening configured for retention of cartridges that is formed when the first portion is lockingly engaged to the second portion by the mechanical interaction of the female locking members and the male locking members. The first segment of the spring retainer and the second segment of the spring retainer collectively form the spring retainer when the first portion is lockingly engaged with the second portion.