Quick-release firearm gas block

A firearm barrel system, comprising:

• a barrel including a gas block journal at an exterior surface thereof, a retention member recess extending through the gas block journal, a bore extending longitudinally along a length of the barrel, and a gas port having a first end exposed at the gas block journal and a second end exposed within the bore;
• a firearm gas block assembly including a gas block, a retention member, a gas tube mounting body, a gas routing passage, and a travel limiting member, wherein the gas block includes a central bore engaged with the gas block journal and a retention member passage intersecting the central bore to define an opening between the central bore and the retention member passage, wherein the retention member is engaged within the retention member passage, wherein the retention member is axially moveable between a first position within which at least a portion of the retention member extends through the opening into engagement with the retention member recess and a second position within which no portion of the retention member extends through the opening into engagement with the retention member recess, wherein the travel limiting member is engaged with the retention member and the gas block for limiting axial movement of the retention member to being between the first and second positions, wherein the gas routing passage has a first end exposed within the central bore and a second end exposed within a gas tube receiving cavity of the gas tube mounting body, wherein the first end of the gas routing passage is at least partially aligned with the first end of the gas port for enabling flow of gas therebetween when the retention member is engaged with the retention member recess;
• and
• spaced-apart surface discontinuities within at least one of the gas block journal of the barrel and a surface of the gas block defining the central bore thereof to define a leakage control zone therebetween within the interface between the gas block journal and the surface of the gas block defining the central bore thereof, wherein the first end of the gas port and the first end of the gas routing passage are exposed within the leakage control zone, wherein the spaced-apart surface discontinuities provide an increased volumetric space into which combustion gas flowing into the leakage control zone from the gas port expand to generate a gas flow perturbance in the leakage control zone for limiting flow of the combustion gas through the interface between the central bore and the gas block journal.