I added the travel stop screw to one of my mechanical frames tonight. It took far longer to read all the way through this thread than it did to do the job....
I modified a couple of steps to suit what I have in stock. First off I used a 10-32 by 1/2 inch long set screw I had for the stop screw. As it turns out this is just about the ideal length. It's also a handy thread size since a lot of paintball parts are held together with 10-32 screws. Bottom line ASA's and drop forwards being two examples.
Also while I drilled and tapped the threads I'm thinking that the next one will be drilled with an 11/64 drill and just force the screw in without pre-tapping the hole. With that close a fit (10-32 screws being 3/16 outside diameter) the screw should go in just fine but with some tension. Enough tension to avoid any moving around from vibration. I'm going to test drill in a different spot to test this before I commit it to the trigger stop screw.
Also if you can't find a 1/2 inch long set screw you can make a stop screw from a longer 10-32 screw. Just cut off a 1/2 inch long section and then use a hacksaw to cut a single slotted cut across the one end to let you use a small flat blade screw driver. CHEAP, CHEAP, CHEAP OH YEAH!
I've got a couple more frames that I want to do this mod to as well. If anyone is interested I could take a new series of pics. My camera does really nice closeups (sorry Darkstar but the pics currently at the first post are rather blurry for the most part).
And has anyone wondered why the trigger has that extra material? I found out that tonight as well. The gun I tried out the new trigger frame on has an older single finger trigger. This older frame uses the pushbutton style side to side snapping safety. The extra material that sticks forward that we are using for the travel stop arm is the arm that hits the old style safety. They just never changed the mold that makes the triggers when they went to the new sliding safety switch method.