People over think this to much. You don’t have to measure the spring height. The only thing to measure is the firing pin protrusion from the bolt face. Set that first. It should be approx .035” from the surface of the bolt face. I would never set it over .040”. (Actually I wouldn’t even set it that high.. it’s a waste!) Next thing it install the spring & the Cocking Piece. Then turn the cocking piece on as far as you can, to get the Cocking Pin (once installed), as close to the edge of the bolt sleeve, in the fired position, as possible. Setting Protrusion to .035” and the Cocking Piece down as far as possible maximizes the firing pin Travel, or Fall, it’s also sometimes called. Firing Pin Travel is a very crucial part of the operation. And it’s often overlooked. The system only starts with roughly .250” to begin with! Setting pin protrusion to .050”+, having the Cocking Piece set way back, not to mention other minor losses, could result in .080” or more could be lost. This is one of the first things I check (besides broken or damaged parts), when addressing light primer strike misfires. Just getting back the full travel could very well fix many of the problems of light strikes out there. Another trick is to thread the Cocking Piece all the way through, and use a set screw in the back of the Cocking Piece. (Picture below) Screw it in until the set screw touches the Cocking Pin. It is threaded 1/4”-28 and I use 3/16” long set screws that I then shorten even more & round the head. This eliminates the play between the Cocking Piece hole & Pin and prevents the Cocking Pin from leaning due to the tension under cocking. Look at it while cocked, you’ll see what I mean. The Cocking Pin will be canted Backwards slightly, thus allowing the Firing Pin to lurch forward and ultimately losing even more Travel.