Just put on a Trophy Ridge Matrix with .019 steel pins. Round pin guard for ease of alignment with peep, has reflective tape on pin guard for easy pick up, The best part is no tools for adjusting once you have the torque set. But, the windage came loose after about 30 shots. There is the gap that the sight slides in for elevation, and that' s right where I had to set sight. After figuring out why I kept shooting left, reset, tightened it up again. So far it hasn' t come back loose, yet. Will shoot more today to see. The vertical pins are cool. I' m not seeing a major problem there. A longer sight bar option would be nice. I did pick this up as an experiment because so many people have asked about it. I' m not familiar with the Copper John sights, but from what I' ve heard they make quality products. I was shooting a Toxonics Hybrid V w/ 9" extension. Once locked down it didn' t move. I' ll give the Trophy Ridge more time. If it comes loose again I' ll contact the company.