An automatic weapon system including a gas evacuation opening formed in a bore of a barrel, a gas evacuation chamber, a barrel immobilizing device, a slide, a weapon frame with guides for guiding slide movement, a return spring mechanism of the slide and the breech. The gas evacuation chamber is disposed at a near-bore space located at the barrel bore outlet, a front wall of the chamber located at the barrel bore outlet is attached at the barrel outlet and having a lower part resting on a weapon frame. A rear wall of the chamber is formed by at least one bridge assembly having one end attached to the slide and another end sliding along the barrel, the bridge assembly is formed by a substantially flat plate having a groove extending from the barrel to the frame and sliding along the barrel, at least one sealing gasket. The frame of the weapon serves as the lower part of the evacuation chamber, the slide serves as upper and side walls of the chamber, a downwardly directed ledge provided at the front of the slide.

An automatic weapon system including a gas evacuation opening formed in a bore of a barrel, a gas evacuation chamber, a barrel immobilizing device, a slide, a weapon frame with guides for guiding slide movement, a return spring mechanism of the slide and the breech. The gas evacuation chamber is disposed at a near-bore space located at the barrel bore outlet, a front wall of the chamber located at the barrel bore outlet is attached at the barrel outlet and having a lower part resting on a weapon frame. A rear wall of the chamber is formed by at least one bridge assembly having one end attached to the slide and another end sliding along the barrel, the bridge assembly is formed by a substantially flat plate having a groove extending from the barrel to the frame and sliding along the barrel, at least one sealing gasket. The frame of the weapon serves as the lower part of the evacuation chamber, the slide serves as upper and side walls of the chamber, a downwardly directed ledge provided at the front of the slide.

Methods, devices and systems are provided for protecting a firearm. The device and system include a protective insert for a rectangular port in a firearm, the port having a length, a width and a vertical thickness. The protective insert comprises a rectangular plate having a top, an underside, two longitudinal sides, and two ends, each longitudinal side and each end having a length sized to allow the plate to freely ride vertically within the thickness of the port. The Protective insert also includes two parallel wing walls, each of the wing walls being perpendicularly attached to the underside of the plate and along a longitudinal side edge of the plate, wherein each wing wall extends beyond both of the plate ends and under the slide when installed. The protective insert fills the port in the slide and rides on, and is held in place, by the barrel when in operation.