The original Finnfire (the mk 1, as it were) is the P94S (the action model number) that you refer to, that was 22lr only and the one that has a strong following as one of the best sporting 22’s. That came in
- Sporter lighter barrel and stock,
- Varmint which had heavy barrel and a heavier beaver tail fore-end stock and,
- Range very few of them and rare/desirable nowadays. They had the Varmint barrel but in a target style adjustable stock that was the same as Tikka MasterSporter of the 1990’s.
All had the same action (P94S) using 9 round mags (in practical usage, not 10!) or 5 round flush fitting, that are a real pain to get out especially from a Range stock.
I have had a Varmint from new, and bought a Range variant recently. They are very accurate and well made as people on SD will attest to. Quad barrels drop straight into a P94S so 17HM2 is an option - I have a cheap Sporter 17HM2 barrel on my Varmint and it mag feeds and extracts fine and adds range over the 22lr. The other Quad calibres (17hmr an 22wmr) are too long for the P94S action/mag.
I don’t know anything about the Finnfire 2 - I’m sure someone will confirm, but I got the impression it was a ‘cheaper to make/dumbed down P94S’ and didn’t last long and doesn’t have the following the original does.
Pictures attached are
1.My Range (cadet target version) but with a normal Varmint barrel in 22lr
2.My Varmint but with the Sporter Quad 17HM2
3. The rare Single Shot Cadet Rifle trial Target version of the Range (about 10-15 exist) with target sights and dual weight barrel etc. Two of these are P94S based and one Quad based.
Once lockdown is over and things easier, I intend to get an integral suppressed/moderated barrel for one/both from Richard Pope. They look like an 18” Varmint weight barrel, but internally moderated.
Hope that helps....I’m sure more people will contribute...