bolts the HK41 bolt features an anti-bounce mechanism that prevents the bolt from bouncing off the barrel's breech surface. The "bolt head locking lever" is a spring-loaded claw mounted on the bolt carrier that grabs the bolt head as the bolt carrier group goes into battery. The lever essentially ratchets into place with friction, providing enough resistance to being re-opened that the bolt carrier does not rebound. The spring-powered claw extractor is also contained inside the bolt while the lever ejector is located inside the trigger housing (actuated by the recoiling bolt). Features The G41 receiver is stamped from a smooth sheet of high-tensile steel rather than the thick sheet steel used by the HK33. The HK41 also had a redesigned bolt assembly. It was designed around 5.56×45mm NATO ammunition with revised geometries between the bolt mechanism components to work with NATO STANAG magazines. It could also use older .223 Remington/5.56×45mm M193 ammunition. The reliable functioning of roller-delayed blowback mechanisms is limited by specific ammunition and arm parameters like bullet weight, propellant charge, barrel length and amount of wear. For obtaining a proper and safe functioning parameters bandwidth Heckler & Koch offer a variety of locking pieces with different mass and shoulder angles. The angles are critical and determine the unlock timing and pressure curve progression as the locking pieces act in unison with the bolt head carrier. The HK41 bolt assembly is lighter than the G33 bolt assembly. The redesigned bolt was paired with a new recoil spring which consisted of five wound strands around a central coil. This reduced recoil. The revised buttstock on the G41 is held in place by two pins. Unlike the earlier HK33, the G41’s pistol grip assembly is not retained by a pin at the front of the assembly behind the magazine well housing and can be removed by the user during a field strip. The spent cartridge casing extractor is installed inside the bolt head, while the tilting lever ejector is contained in the trigger housing. The rifle is hammer-fired and has a trigger group with a fire control selector that enables selecting safe, semi-automatic, burst and continuous fire modes. The fire selector's positions are marked with bullet pictograms and it also serves as a manual safety against unintentional discharge. The selector is ambidextrous and its lever is mirrored on both sides of the trigger housing. In the "safe" position, the trigger