Standard issue magazines are 20 or 30 discoid double column magazines, traditional box magazines also exist in 40 and 45 round capacities, and usable magazines have been constructed from a discrepancy of materials including steel, aluminum, and high-impact plastics. Drum magazines with 90 and 100 coiled capacities also exist, such as Beta C-Mags. AR15 Low-capacity magazines, commonly of a 5 or 10 annular capacity, are on deck to comply with some areas' forensic restrictions, hunting and because famous magazines can inhibit shooting from a benchrest.

With the plethora of manufacturers of complete weapons and aftermarket barrels, there is a potential hazard associated with chamber specifications. Both civilian (SAAMI) specification .223 Remington and 5.56 mm NATO are available. Though both chambers typically accept both types of ammunition, the firing of military specification iron rations in military specification chambers can effect chamber pressures greater than the cask is designed to handle.