[Lonestar57]

As noted above possible causes; dirty, weak, broken, or worn Sear Spring. A worn Sear or worn Hammer (Sear notch). But there is one other thing to check. The Sear Spring Clip; part of part number 31. Open the link dfariswheel provided on the schematic above of the Colt .380 and you'll see it as # 31 with an arrow pointing to it and the Sear Spring. The reason it doesn't have a separate part number is that it was an engineering afterthought to prevent the Sear from slipping causing the Hammer to fall forward unintentionally. Over the years I've seen a number of used Colt Mustangs and Government .380 models that don't have this Sear Spring Clip. It's an easy check and fix if needed. First, see if it has one. Secondly, if it does have one check it for wear or being too loose. It should be properly holding the Sear Spring in place tight. To remove it gently pry one side of the Clip up and off one edge of the Sear Spring using a small screwdrver. To re-install make sure the Sear Spring is pushed up and properly positioned in the grip frame. Using your finger press the Sear Spring into position over the Sear Spring. You should feel and hear a distinctive click as the clip seats over the Sear Spring and the Sear Spring should not be able to have any downward movement. Here's are pics of a leaflet that came with part of the paperwork that Colt placed in the boxes for a period of time. If you need one check Brownells since they have them in stock from time to time. Colt is no longer offering the clips or installation. Just thought you might want to check this first before looking at any other part replacements. Good luck