A very old S&W Mod 36. A Flat Latch. I still have the original numbers matching walnut grips, long ago sanded smooth and varnished for snag free concealment by the original LE owner. A fine shooter with most of its original finish....just a touch of endshake in the cylinder. An easy remedy and this handgun will be as tight as new in 15 minutes. The 10 thousands gauge is a very tight interference fit. The 9 thousands gauge just barely slips between cylinder and barrel with the cylinder held fully rearward. There is visible fore and aft shake in the cylinder along the yoke axle with the gauge removed. Too nice a gun to allow it to continute be battered with each shot. Stainless steel shims, 2 thousands thick. They come in packs of 10 and I should only need one. So, since they are long lasting and I only need one....guess I'll have to find several more S&W revolvers to tighten up..... Remove the yoke and cylinder from the frame. Disassemble the extractor mechanism from the cylinder. On the J frame Smith, the threads are reversed....Righty Loosie, Lefty Tighty gets it apart.