I use a variety of Wagner force gauges for measuing triggers and recoil springs.
They cost too much new, but I get them surplused by industry on Ebay.

$560 new
https://www.radwell.com/Shop?source...lZEw9hRYkfoxchyN3YdPqA_s9VRoCv_sQAvD_BwE


$25 used
https://www.ebay.com/i/333136624383?chn=ps&norover=1&mkevt=1


There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. -Ernest Hemingway
The man who makes no mistakes does not usually make anything.-- Edward John Phelps