Abstract: A stabilizer for use in a blast hole drilling has a shaft connectable at each end to a drill string. A plurality of individual bushings are axially spaced along the shaft, and each bushing carries a roller reamer rotatable thereon. Each bushing has its inner bore eccentrically positioned relative to its outer surface, and each bushing is mounted to the shaft so that its major eccentricity is angularly offset from that of the other bushings. In this manner, large diameter roller reamers can be used and the rotational speed thereof is reduced thereby reducing wear and increasing life. There are sufficient rollers such that the stabilizer is centrally supported in the drill hole and will not waver as it rotates.