I purchased this item for use with my Taurus PT1911, and had issues adjusting the sight for accuracy. It is adjusted vaguely with an Allan key on the side and top and I could not get it to adjust onto target. I then removed it from my PT1911 and put it on my Marlin 336 Lever rifle, and continued to have accuracy issues. I could not hit a 4" square steel target at 50ft with it. It is my belief that the sights adjustment shakes loose every time I fire the weapon. I do not suggest this product for use on anything more than an airsoft gun.
Ax Maxwell from