US Patent 10458733 Bolt mechanisms and firearms containing the same

A firearm includes a bolt mechanism with a bolt configured to receive a firing pin assembly and a bolt head assembly. The bolt head assembly includes a pivoting bolt head and an extractor. The extractor is positioned relative to the bolt such that substantially all forces applied by the extractor to the bolt mechanism are reacted within the bolt head assembly. A biasing member or element can urge a claw portion of extractor towards a distal end of the bolt head.