A semiautomatic shotgun successfully uses the AR-10 receiver and the superior direct impingement gas system. A combination of locking lugs to maintain proper sequencing, a spring disposed inside of a gas impingement chamber, and a spring to cycle the action. Fouling is avoided using nickel-boron coated parts, permanent infusion of a dry film lubricant, and an angled gas port. A unique magazine feed lip and barrel extension feed ramp and the magazine maintaining the shells at a slight angle upward, and a bolt face having a rear facing partial bevel avoid jamming and snagging. The present invention also teaches raised gas tube and gas key to accommodate the larger bore of the shotgun. The combination achieves an AR-10 based shotgun which has the advantages of direct impingement cycling (less recoil, greater accuracy, etc) without fouling and/or jamming.