Just sharing some info that I hope some folks will find useful.
This site is obviously dedicated to NRA Highpower Rifle. However, there is just a wealth of articles on many topics, including springs. All of them are in PDF format and free to download.
http://www.zediker.com/default.html
I have a Ruger Mk I standard 22 pistol that I bought new in 1974. Today it is pretty much "Kentucky Fried"--parts is parts--to include a SS AMT heavy barrel top end. I managed to snag the AMT before Ruger took offense and legal action--"I say lads, I believe that's our patent you're infringing on".
Recently I had begun to notice a sharpness in the recoil, metal contacting metal. Obviously, the bolt was starting to slam into the bolt stop pin. So I got on of these kits--
https://volquartsen.com/inventory_configurations/1086
I simply installed it as it came with the standard weight spring. I went to the range and tested it out with this ammo--
https://www.brownells.com/ammunition/rimfire-ammo/superextra-high-velocity-ammo-22-long-rifle-40gr-cprn-prod82595.aspx?avs|Cartridge_1=AFF_22+Long+Rifle&avs|Manufacturer_1=aguila
Flawless function, no more metal on metal. My main point is that this kit DOES in fact work for the MK I, even though Volquartsen does not list it.