I have a Keller and like Lilhunter said you got to watch the free moving sight. Two years ago we were in a bad snow storm and my sight got covered, I blew the snow off. Mistake, my breath blew most of the snow of but frooze up might sight. I didn't realize this until I was at full draw. I put my arm down and I was like...hold on something isn't right. The pin never swung. I still use the sight and really like it for the most part but know I always check to see if I'm moving freely. Good Luck!