DURAMAG has solved the geometry and durability problems of putting straight-walled, big-bore rounds in a magazine designed for smaller, tapered cartridges by simply not doing it. Unlike other stop-gap solutions such as after-market followers or springs, the DURAMAG .450 Bushmaster is a complete solution designed from the ground up to properly support the round in a magazine that fits into the AR15 magazine well. Until now the challenge has always been the magazine. While originally intended to fit a standard AR15 magazine, improper geometry and follower design has led to feeding issues and rifle malfunctions. Some home-remedies worked, but the unique stresses caused Mfg: C-Products