Definitions by Anonymous
bolt
The assembly on most SMG and larger-class firearms that is responsible for the chambering of a new round, as well as the extraction of the spent casing. It is usually mounted on one or more spring-loaded guide rods, and is operated by a number of ways. From using the recoil force of the exploding powder charge to being manually pulled backwards and then forwards to battery again, it is an essential part of any automatic firearm.
P90
Manufactured by Fabrique Nationale, one of the top leading arms companies of Europe, the P90 is FN's answer to NATO's request for a compact Personal Defense Weapon system that will defeat armored targets, which in the modern battlefield is becoming more proliferous. A bullpup design, the P90 boasts complete ambidexterity, with ambidexterous fire selector, magazine release, and downward casing ejection. Most unique about the weapon is its 50-round magazine, mounted vertically parallel to the barrel, the cartridges are actually rotated 90 degrees in the magazine before entering the chamber. This round, the 5.7 x 28 mm (a necked-down 5.56 x 45mm), is being touted as the answer to kevlar-wearing opponents, being able to pierce 48 layers of CRISAT from a range of 200 m. With a dual-composition steel/aluminum core, the 5.7 will tumble upon penetration of soft tissue, leaving deep cavities up to 2-3 inches. Despite this, the relatively low muzzle energy and mass of the 5.7 round sometimes prove unreliable in terms stopping power against unarmored targets, unlike the venerable .45 ACP, or even the 9 mm Parabellum.