Hi,
I don't believe there is a tutorial specific to sear springs but it may be covered in lock building threads. Sear springs are not hard to make but it is best to use good spring steel like SAE 1075. I don't what size spring you need so you have to gauge the length. The spring should touch the top of the sear just behind the bolster on the sear for the screw. Spring steel about 1/16" thick should work. Cut it a little wider than you need so you are able to make the tab that fits into the slot on the lock plate. Make the ring first. For a #6 screw the hole diameter must be at least 0.13" so if the steel is 0.0625" thick (1/16") the outside diameter of the ring is 0.13+0.0625+0.0625= 0.255". Multiply that by 3.14 (pi) = 0.8". That is how much spring steel you need to allocate for the ring. Mark that length off. Heat that tab red hot with your torch and bend it up about 45 degrees. I use unthreaded screw blanks of the diameter I need mandrils but you can also use a long screw of the size you need. It just has to be long enough to be held firmly in a vise and used as a mandril for bending the spring steel. Put the mandril in the vise, heat the spring red hot and use needle nosed pliers to bend the steel around the mandril. Once the ring is made, file the spring and ring thinner except at the tab. At this point I polish up both sides of the spring while it is still flat. Then determine where the bend goes. Anchor the ring in a vise and heat to red hot at the bend, use your pliers to bend it into a narrow "V". If I want the bend to be very tight, I hold the spring in pliers, heat the bend to red, place the bend on an anvil and tap it closed with a hammer. Try fitting the spring to the plate with the sear in place to adjust the length of the lower leaf and file it until it almost touches the sear bolster. Open the bend or bend the lower leaf down so it applies enough pressure on the sear. Once fitted, heat the spring red hot, quench in oil and then polish off a flat surface so you can see clean steel clearly. Then heat the spring very slowly with your torch and watch the color changes in the steel. It will progress from yellow to bronze to purple to deep blue and then the blue will lighten to a sky blue. At that point stop heating and let it cool. You can also temper it by dipping it in oil and flaming the oil with your torch. If you do that 2 or 3 times it should be tempered. I prefer to watch the colors.
dave
