It was a sunny 40-ish degrees this morning so I took my AR to the range to sight in the Viridian HS-1. My first observation was that like the red lasers, the green laser is very difficult to see in the daylight. I don't know how you managed to zero it at 100 yards. I couldn't see the dot any further out than 15 yards. Did you zero it indoors? The next obstacle was self inflicted. When I mounted it I was hesitant to torque the screws down too hard. It is after all plastic. So after the first couple shots it was clearly no longer where I had put it. I didn't remove the screws and reapply the blue Loc-Tite, I just tightened the screws down as much as I dared and it stayed put for the rest of the session. Originally I set the laser in line with my red dot for windage and I noticed that after I had it zero'ed it was no longer in line. So I rechecked the red dot and sure enough it was my red dot that was off a little. Maybe 1/2". So I adjusted the red dot and all is well. I'm not overly concerned about the laser being zero'ed at 15 yards since that is likely about the distance I would need to use it at anyway, but I won't lie, I was a little disappointed that I couldn't see the dot at 25 yards, much less 50.