Best short-range varmint gun?

[Zebo]

Walther P22 is best 22 made... high cap 15 rds and built well. Ruger is good for a boat anchor as heavy as it is.

 

[GaryJohnson]

Various combinations of subsonic rounds and semi-automatic .22 LR firearms result in unreliable cycling of the firearms' action, as the result of insufficient recoil energy.

That mirrors my experience shooting subs in my Buckmark. ymmv

Edit: Also, here's my Buckmark:

Having also shot a Mark III and a P22, I would not trade it for either. The "best" .22 pistol might be this Volquartsen: https://www.volquartsen.com/products/553-v-10-x But I don't know anybody that would pay that much for a .22.