Know how your gun is put together
By James Nicholas
If your are going to work on a pistol make sure you know how the parts are put together. A simple and easy way is to check a schematic. This shows all of the parts of a firearm and how they fit together. We had a customer send us his Shield. His new sights had been installed in from the wrong direction. The installer ended up crushing the drop safety spring making it look like a headless jack in the box.
This must be common occurrence with Smith & Wesson M&P pistols. They have since updated the parts, making it easier for almost anyone to be able to reassemble the slides without needing three hands. Before the Safety Block had three parts--the Safety Block, SB Spring, and SB Cap. The New SB Cap is now plastic but has a small nipple on the bottom that fits into the SB Spring. This keeps the parts together and aids with reassembly. Before the cap could easily slip off the spring unless you had the proper tool for reassembly.