A blade trigger can be cobbled from the stock Kingman trigger fairly easy. All you'll need is a dremel with attached sanding barrel or you can simply use a file. A dremel will make the task much more simple as the sanding barrel will cut through the cast aluminum trigger like butter. There are better versions for sale on the market **ahem........SPPS Magno's** but if you don't have the cash for such items this mod will make the stock version much easier to walk after removing the finger hump. I made my first over 2 years ago and was time well spent especially having a 50 gram micro switch to accompany it. If you leave the spring out you can get an even greater rate of fire but there's a chance of misfires due to the heavy nature of the cast aluminum Kingman trigger. The weight can inadvertently depress the micro switch button and cause misfires by jarring your marker, running with it or even tilting it back with the barrel pointed upward. You can evade that by cutting and stretching the stock trigger spring and leaving it in. The result would be a lighter pull than the stock configuration yet it would still keep the trigger away from the micro switch button to evade any possible accidents. Some tweaking would be required to get it to your comfort zone.
Modifying The Trigger
Chuck the top portion of the trigger in a vice using 2 small blocks of wood or 2 pieces of corrugated cardboard to prevent it from being marred. Start by removing the middle hump from the stock trigger. Try to make a straight line from the low point tangent of the first finger groove to the second. If you'd like to lighten the trigger a bit more you can flip it over and try to flatten or thin the back portion as well. You don't want to take too much material from the thickness because you don't want it bending or breaking. Cast aluminum is brittle and will break much easier than regular aluminum stock. I've made mine as thin as 1/8" and had no problems with breaking them. Don't test it because chances are you will break the trigger in two.
Optional Addition
Optional: After cutting the humped trigger flat, install it but don't put the trigger pin in all the way. Push the trigger back and find a good spot below the button of the micro switch that you want to have the back stop adjuster in. Mark the side of the trigger with a sharpie marker or similar. Remove the trigger and mark this point on the newly flattened area that you just made. Find the center point of the trigger and use a center punch to start your drilling point. I would suggest not using any larger than a 4-40 or 6-32 set screw for the backstop adjuster. You must use the appropriate drill size for the tap used or you will either ruin the tap or break it off if the hole is too small or the set screw will be very loose if the hole is too big. Be sure to saturate the tap with tapping oil as well while tapping the hole. The 4-40 tap uses a .0890 #43 drill bit and the 6-32 tap uses a .1100 #35 drill size. Chuck the whole trigger in the vice then drill and tap where you made the mark. After the next step, use some blue Loctite to keep the set screw in place.
Final Touches
Now all you need to do is use some 800 - 1000 grit sandpaper to remove and smooth out the file or sanding drum marks in the trigger. Use a metal polish for the final surface sheen. This trigger will not stay shiny because the sweat salts from your fingers will continually make the raw metal tarnish. You'll either have to continually shine it or deal with the fugly grey tarnish, your choice. Adjustment procedures for the trigger can be found in the tech section of our site.
Technical Information
