An arcuate magazine for a firearm, such as a rifle or carbine, which has a keyway and follower assembly for delivering rounds of ammunition one at a time to the firing area of the firearm and which may be fabricated from a single piece of metal and have a smooth interior free of welds and rough spots. The invention also includes a method of making such a magazine which includes the steps of deep drawing and wiping the magazine body under substantial pressure using a progressive die having numerous stations.