If the rear sight is loose, there are two screws that hold the bottom base of the rear sight to the barrel. If you take the center screw out of the adjustable model of sight, there is a spring under that inside blade and the back part of it is pinned to the base of the sight. Careful you do not loose the small spring. It fits into two small indentations on the two parts of the sights. You can drive the pin out of the back of the sight and then removing that center screw the inside part will come out and give you access to the two screws that lock the base to the barrel. Sometimes, those screws will come loose or even rust and break off. You then have to contact T/C and they will give you some new screws. If you feel competent, take the rear sight apart and check the screws inside that hold the base tothe barrel. I just recently had to do that to a Renegade because one of the screws actually rusted off. I never take the rear sights apart. Over the past twenty years, that one back screw finally broke and the sight would not stay tight.