I've recently put them on my SBH 4 5/8 .44mag, and love them. I have a lot more confidence in the hole than I do with a notch sight. I have only put about 2 boxes of shells through it so far, so the groups are not yet what I can accept but that problem is me, not the gun. About 4 inches at 25 yards with the larger of the two apertures. It will get better, I know.