US Patent 8931196 Firearm having capability for field assembly and disassembly

A firearm having modular components that can be assembled under field conditions, by using simple tools. Upper and lower receivers are assembled by pins and a barrel and gas tube are secured to the upper receiver by a barrel nut. Mounting flanges of the upper receiver and a handguard are secured in reliable assembly by a manually actuated clamp mechanism having a clamping condition releasably securing the handguard to the upper receiver and having a releasing condition permitting separation of the handguard from the upper receiver. A pocketed soft protective container receives and protects the modular firearm components until firearm assembly takes place.