Cylindrical rifle handguard assembly

A handguard assembly for a rifle barrel comprising:

• first and second shells having generally semicylindrical shapes, each shell having a plurality of vent holes arranged in a longitudinal row in the center thereof extending substantially from the front to the rear of the shell, the first shell being adapted to be placed over the top of the barrel with the sides of the first shell disposed laterally of the barrel and the second shell adapted to be placed under the bottom of the barrel with the sides of the second shell disposed laterally of the barrel in mating engagement with the sides of the first shell so as to define a generally cylindrical handguard around the barrel, the front and rear of the shells having surfaces for mounting the handguard upon the barrel and clamping the first shell and second shell together to hold the sides thereof in mating engagement;
• a first liner, having a forward segment and a rear segment, of generally semi-cylindrical configuration mounted in the first shell, the forward segment of the first liner having a plurality of vent holes which define a centrally disposed longitudinal row, the vent holes in the forward segment of the first liner registering with certain of the vent holes in the first shell for cooling the barrel, the rear segment of the first liner covering the adjacent vent holes in the first shell and having a flange which projects from a side thereof;
• and
• a second liner, having a forward segment and a rear segment, of generally semi-cylindrical configuration mounted in the second shell, the forward segment of the second liner having a plurality of vent holes which define a centrally disposed longitudinal row, the vent holes in the forward segment of the second liner registering with certain of the vent holes in the second shell for cooling the barrel, the rear segment of the second liner covering the adjacent vent holes in the second shell and having a flange which projects from a side thereof, the flange of the second liner overlapping a side of the first liner and the flange of the first liner overlapping a side of the second liner for radially sealing the annular volume between the barrel and the rear segments of the first and second liners to reduce heat flow to the rear portions of the shells where a user's hand may be placed.