Taipan Veteran regulator adjustment/air drain

If I’m not mistaken I think you need to remove the hammer spring also.
That makes sense, although I don't remember doing so. I guess it might depend on the length of the screw "extension", and how much spring tension has to be overcome to open the valve. But as I think about it, I'm sure you're right, there's certainly no need to leave it in.
 
Elh0102 has the right idea. I believe I saw it on a video online but they, and now I, use one of the 2 side plate screws. The plate is covering the trigger linkages. Put screw threads first into hammer spring adjuster hole that faces hammer (I’m using the donny fl) and tighten till air releases. I leave it that way for 30 sec to a minute. Make sure unloaded and pointed safe direction.