Gamo, benjimen and Beeman are three good brands to go with. A break barrel that travels 1000 fps is ideal for squirrels. I personally use a Gamo shadow 1000 for squirrel hunting.

go onto the gamo website and check out their new 22 air rifle. that thing can bring down a boar! have fun shooting chipmunks.

any .20 or higher caliber air rifle will do. I would use hollow point pellets though.

gamo

I have a Winchester (branded Daisy adult) air rifle that is dead accurate. It's the 1000SB.

I've had air rifles that seem to lose power over time, like seals weakening, or pumps just don't move enough air anymore, but this one is 6 years old, had thousands of Beeman hunting pellets through it, and still works like new.

I have a Ruger Airhawk. 1,000 FPS with .177 hollowpoints. Shoots 1 inch groups ay 50 yards with the supplies 4X scope. It gets the job done neatly and quietly.