Cant see the point of .20 when you have light pellets in .22 and heavy pellets in .177
Falcon accuracy plus .22 13.3 gr running @ 625 fps very good in most guns
JSB heavies .177 10.3 gr running @ 715 fps very good in most guns

I use falcons in my .22 guns
AA Express 7.9 gr in my .177 and kills rats , squirrels , pigeons , rabbits from 15 yards out to 50 yards