Abstract: Disclosed is an integrally suppressed barrel which in an embodiment includes a firearm barrel, an outer sleeve, a front end cap, and a plurality of mesh layers. The firearm barrel has at least one set of hole groups to provide venting of propellant gas to a first space between the firearm barrel and the outer sleeve. At least one hole of at least one of the sets of hole groups is sized and threaded to mate with a removable socket head plug and are configurable by the user to vent, or to not vent, based both upon attributes of the ammunition desired for use and upon the desired degree of suppression. The holes of the at least one set of hole groups are elements of an open path for the gas, from behind a fired projectile, to outside the integrally suppressed barrel, as the projectile traverses the bore of the firearm barrel. Movement of the gas vented from forward holes dampens movement of the gas vented from rear holes. The plurality of mesh layers is located in the first space.