.22's are individuals
RatShooter made the observation that his Ruger 22/77 shoots until it gets fouled, but comes right back after cleaning. My 22/77 in .22WRM is the exact opposite. If I give the barrel a good cleaning, the first five round group @ 50 yds will shoot 1 1/2", next 1 1/4", etc. Usually takes about 6 five round groups until it tightens up & starts putting five rounds into the 1/4" range. I've gotten to the point with it that I just run a Hoppes bore snake with a bit of Remington bore cleaner on it down the barrel 2 or 3 times after a shooting session & let it go at that.
By the way, I'd mentioned that my Henry Lever had shot some 1" groups @ 50 yds with CCI Mini-Mags so I decided to try some better ammo in it. Well, results were interesting, to say the least. CCI Green Tag put 3 rounds in a 4" group, & 2 rounds completely missed the paper, (5X7 paper sheet). CCI Standard Vel produced a 3 1/2" group & Wolf MT got me a 2" group, go figure ! The lesson being, one can take an educated guess but you can never be 100 % sure what ammo any particular .22 LR firearm is going to like, just gotta keep trying until you stumble onto it.
I'm in that process right now with my CZ 455 Varmint, & so far it seems to like Federal Gold Match, closely followed by Wolf MT but I've still got about 12 different boxes to try. It really doesn't like anything from Eley or Remington, that's for sure.