Works as advertised!
Trigger unit: (that light striker, weak spring, and a tiny gas port on the valve is makes this one a 4.5-5 foot pound rifle, but with 80-90 shots per 12gr.)
Used harder plastic shims in various thicknesses (mostly from 12gr shells/ wads). Not really compressible, but I didn’t have anything “squishy” in the right thickness.
No real trigger gauge, so I “cheated”.
TRIGGER PULL GAUGE CHEAT:
With rifle captured loosely between thumb and fore finger, pointed down, on top of a digital kitchen scale, the weight of the rifle is 6 pounds 10 oz. CAREFULLY and SLOWLY pulling up on the trigger and watching the scale read out, can get the weight where the sear tripped. Difference between the two would be the trigger pull.
Had worked this trigger over for smoothless and a crisp pull, so it’s starting off way-better than a stock 387/392. Never did anything about the take-up as it never really bothered me; it’s not 1st stage as there is nearly no real weight to it, but what weight it adds to the trigger pull is minor (scale claimes it is something like 1 ½ to 2 oz).
As tuned: 1 pound 8oz.
.032” shim = 1 pound 2 oz.
.054” shim = 14oz. BUT, the trigger malfunctioned about 2 out of 5 tries.
Evidently the .054" shim as a little too much. If I used a compressible shim, could just change the shim thickness by how tight the unit was attached, but as I was using firm shims, decided to back track to the .032” shim and a 1 pound 2 oz. pull. Boucned the rifle around on its butt and it didn’t fire. Will see what it turns out to be in pull (and safety) once the sear has mated up to its new angle.
May go to a "split the difference" shim thickness later.