Hi Rhys , I love the .20 cal my most used sub 12fpe airgun is my Daystate Huntsman classic
in .20 cal with H&n FTT pellets its hard hitting ,accurate trajectory amost as flat as.177, i also own and shoot a HW95 springer in .20 cal . people knock this calibre without trying it . i can say truthfully i have had no runners when a .20 pellet hits a bunny in the head its DEAD!!!
i am biased i am converted to this cal .
atb brian
ps. i own and shoot all the other calibres as well even a .303 fac airgun
now that is awsesome!!!!!