A thermal mirage reducing device for firearms is disclosed and described. The thermal mirage reducing device includes a heat control shell oriented along a horizontal longitudinal axis corresponding to a bore line of a firearm. A cross-sectional profile of the heat control shell taken perpendicular to the longitudinal axis is asymmetrical about a vertical plane dividing the heat control shell along the longitudinal axis. The cross-sectional profile has a heat-directing portion protruding on one side of the vertical plane. The heat-directing portion extends to a high point that is vertically higher than any other point in the cross-sectional profile and laterally offset from the vertical plane. The cross-sectional profile does not intersect the line of sight of the firearm.