Systems and methods for an adjustable gas block are described. Systems may include an adjustment subassembly. The adjustment subassembly may include a valve stem end with a front-most portion larger in diameter than the rear-most portion and a boss extending from the forward portion of the valve stem end; a valve ring surrounding the boss of the valve stem end; a valve threaded portion for receiving the boss of the valve stem end and having a threaded portion; and a valve rotator coupled to the valve threaded portion for adjusting the flow of gas. Systems may include a gas block assembly. The gas block assembly may include a gas block through hole; a first duct to direct pressurized gas from a barrel to a plenum; a second duct to direct a regulated volume of gas to a gas operating system; a seat valve to control the regulated volume of gas to the gas operating system; and a gas block threaded portion for coupling to the valve threaded portion. The adjustment subassembly may be coupled to the gas block assembly.

A firearm, in particular handgun, has a barrel mechanism with a barrel and a chamber, a closing mechanism with a slide and also a cylinder-piston mechanism for gas pressure-operated closure delay. The cylinder-piston mechanism has a hollow cylinder with a hollow cylinder wall. A channel is formed between the barrel mechanism and the cylinder-piston mechanism. The hollow cylinder wall is fitted with at least one reinforcing element. The firearm may be produced by the following process steps: introduction of a first portion of the bore into the basic body up to the recess; introduction of a second portion of the bore up to the hollow cylinder; drilling of the channel, wherein the drill is conducted through the bore; and introduction of the reinforcing element into the recess, wherein the bore is closed in a gas-tight manner.