This is a 7-round steel magazine chambered in .450 Bushmaster. Duramag magazines are made from a single piece of laser-welded 410 Stainless Steel and protected with T-360- applied coating. This is a magazine that can truly withstand the test of time and hard use. C Products Defense took great care to design this magazine to be the best option for precision shooters but also for heavy full-auto use. Precision shooters will enjoy an incredible amount of load length for their long-range shooting while knowing that their magazine will also feed as fast as needed, every time.