I have had non PCP air rifles in .177, .20, .22, and .25" and the only one I kept when I moved cross country is the .22.
The 177 are great but the .22 kills better.
I love the .20 but it's not well supported by the ammo people so ammo is limited..Thanks JSB for keeping it well fed!
The .25 delivers a big pellet but in a springer or nitro-piston rifle, trajectory is compromised and holdover is more critical.
I kept the TX200 in .22.
It's not the fastest or the biggest or even my favorite, it just works!
Take a look at JSB's Hades pellet for varmints, only available in .22 and .25. Coming soon in .177 and it'll help!

Last edited by colodog; 04/11/20. Reason: add comment
"Camping places fix themselves in your mind as if you had spent long periods of your life in them.
You will remember a curve of your wagon track in the grass of the plain like the features of a friend."
Isak Dinesen