Sav300 - The Williams receiver sight in your photo is the model FP-99S which was designed to be mounted in rear two scope mount holes in receiver on tang safety M99's since those rifles do not have the tang sight holes in the tang because of the tang safety. Use of that sight and the Lyman model 57SB sight on an earlier model with the lever safety will result in covering up the cocking indicator on those earlier rifles. Don't know if that would result in damage to the "innards" of those rifles but it definately eliminates the effectiveness of the cocking indicator stud. The correct sights for lever safety M99's are: Williams FP-99, Lyman 57SA, and Redfield models 70L and 80L. Williams also has made a "cheapie" line of receiver sights sold as the "5D" line but none were made for the Sav M99.
