how does the magazine on a p90 work
FN P90 The P90 uses a unique horizontally mounted feeding system—patented in the United States—that contributes to the weapon's compact profile and unusual appearance.[12] U.S. Patent 4,905,394 ("Top mounted longitudinal magazine") was awarded in 1990, naming René Predazzer as the sole inventor.[31] The detachable box magazine is mounted parallel to the P90's barrel, fitting flush with the top of the weapon's frame, and it contains 50 rounds of ammunition which lie in two rows facing left, offset 90° from the bore axis.[17] As the cartridges are pushed back by spring pressure and arrive at the rear end of the magazine, they are fed as a single row into a spiral feed ramp and rotated 90 degrees, aligning them with the chamber.[17] The magazine body is composed of polymer, and it is semi-transparent to allow the shooter to see the amount of ammunition remaining at any time.[17]
Smith & Wesson M&P15 The M&P15 was unveiled at the 2006 SHOT Show, it debuted in two varieties: the M&P15 and the M&P15T.[5] Both are basically the same rifle, chambered in 5.56×45mm NATO, with the T-model featuring folding sights and a four-sided accessories rail fore end. They include the standard direct impingement gas system. In order decrease cost on the original design both the dust cover or forward assist were omitted. These rifles were initially produced for S&W by Stag Arms, but marked and marketed under the Smith & Wesson name.[5] Currently, Smith & Wesson makes the lower receiver in-house, while the barrel is supplied by Thompson/Center Arms, an S&W company acquired in 2007.