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 new 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 by this load typically deformed the magazine after just 10-20 cycles. - Thousands of rounds from a single magazine of in-house and third-party testing by firearms manufacturers have confirmed DURAMAG is the answer. An advancement in magazine design and construction has made this possible. By creating a proprietary internal bracing system and laser-welding it into a 410 stainless-steel body DURAMAG is able to control round stack and prevent misalignment when rounds attempt to double stack. DURAMAG