I just bought the Daisy pellet gun for my 5 yr old.
http://www.walmart.com/ip/Daisy-Mode...Rifle/15730095
The stock is a little too long for him yet and he can't freehand it up when it's full of bb's but he's a great shot at 20yrds off my shooting bench.
He'll be ready for the 10/22 by summer.