Patent ID: 7707763

Claim:
A gun barrel assembly comprising: a gun barrel having a muzzle opening on a distal end; a shroud coaxially surrounding at least a portion of the barrel, the shroud having: a distal portion extending beyond the muzzle opening defining a shroud front region having a distal end portion, a proximal portion extending proximally from the muzzle opening defining an annular region between the barrel and shroud, a front wall disposed at the distal end portion of the shroud, the front wall having an opening to allow passage of a projectile fired from the firearm, and circumferential holes in the proximal portion of the shroud; and a moveable firewall disposed in the annular region of the proximal portion of the shroud, the firewall moveable between a forward, at-rest position, and a rearward, compressed position; whereby gases generated during fire compress the firewall rearward forcing air out of the annular region proximal to the firewall and allowing expanding gases generated during fire to escape out of the circumferential holes distal to the firewall.