As many of us are aware, the firearms designs in the original Marathon game were less than wholly realistic, to put it mildly! Lacking the later influence of Rob McLees on Bungie's more grounded portrayals of weaponry, many of the guns of the first game were, if not very believable even within the setting, rather awesome.
Being a lifelong firearm history aficionado, I thought it would be an interesting exercise to produce a simplified little spec document for the iconic .44 Magnum Mega Class from the first game, the goal being to justify the design somewhat logically and fit it into known lore material. My self-imposed mandate was to include all extant canon material while expanding it and creating something that might technically function and perform the feats we see in the game, such as penetrating Hunter armour and functioning reliably in vacuum. An artist I am not, but I think I get the point across.