A shotgun shell magazine configured for use in a lower receiver of an M16/AR-15 military specification a.k.a. mil-spec firearm, the lower receiver of the mil-spec M16/AR-15 firearm configured to strip a shotgun shell from the magazine and load the shotgun shell into a chamber, the magazine comprising: a) a magazine body (130, 130') including a front panel, rear panel, forward edge and rim edge defining an open top end and a cavity proportioned to slidably receive one or more nominal 6.35 centimeter (2.5 inch) long.410 bore shotgun shells, an external step formed on the front panel, rear panel, forward edge and rim edge, the step dividing the magazine body (130, 130') into a magazine well portion and an external portion, the magazine well portion configured to be detachably received within a mil-spec magazine well on the lower receiver of the mil-spec M16/AR15 firearm, a feed lip extending upwardly from each of the front panel and rear panel, each feed lip configured to partially occlude the open top end proximate the rim edge, a feed lip wall joining each feed lip on its respective front or rear panel (208, 210) to the rim edge, the rim edge including a vertical edge strip extending from the feed lip walls to the external step on the rim edge, the vertical edge strip, feed lip walls and each front and rear panel (208, 210) defining a closed gap (204, 206) in communication with the cavity; and b) a follower resident within the cavity and having a ramped upper surface, the follower being biased toward the open top end whereby, when the magazine is loaded with one or more shotgun shells, a top most shotgun shell is angled with respect to the open top end and at least a portion of a closed end of the top most shotgun shell lies above a plane created by the open top end of the magazine body (130, 130'). a) a magazine body (130, 130') including a front panel, rear panel, forward edge and rim edge defining an open top end and a cavity proportioned to slidably receive one or more nominal 6.35 centimeter (2.5 inch) long.410 bore shotgun shells, an external step formed on the front panel, rear panel, forward edge and rim edge, the step dividing the magazine body (130, 130') into a magazine well portion and an external portion, the magazine well portion configured to be detachably received within a mil-spec magazine well on the lower receiver of the mil-spec M16/AR15 firearm, a feed lip extending upwardly from each of the front panel and rear panel, each feed lip configured to partially occlude the open top end proximate the rim edge, a feed lip wall joining each feed lip on its respective front or rear panel (208, 210) to the rim edge, the rim edge including a vertical edge strip extending from the feed lip walls to the external step on the rim edge, the vertical edge strip, feed lip walls and each front and rear panel (208, 210) defining a closed gap (204, 206) in communication with the cavity; and b) a follower resident within the cavity and having a ramped upper surface, the follower being biased toward the open top end whereby, when the magazine is loaded with one or more shotgun shells, a top most shotgun shell is angled with respect to the open top end and at least a portion of a closed end of the top most shotgun shell lies above a plane created by the open top end of the magazine body (130, 130').