A .22 handgun is also good but I don't have experience with them. In fire drills I've done with a 9mm handgun and an AR-15, I was able to put more rounds on a target faster with the handgun. The only thing I don't like about practicing with the 9mm alone is that I'm not really shooting from different positions, only a standing stance. The rifle encourages you to crouch or lay down which I prefer when shooting.

edit: As for rifles, I personally love the X-22 backpacker stock for the takedown version of the 10/22: https://magpul.com/x-22-backpacker-stock-ruger-10-22-takedown.html . The rifle is so light and versatile while breaking down into a small daypack. The stock has a watertight compartment for a small survival kit. Unless I'm in grizzly bear country, it's the one gun I'd bring into the backwoods.