I agree that it's tough to outfit a 9 year old with a proper fitting rifle. I started out with a borrowed Winchester 94 in 30-30 at age 14. It's a well balanced cartridge. Remington makes a Managed Recoil load for 30-30.
In 1969, Dad bought a Remington 760 pump rifle in 243 for my brother and me to share. We mounted a second hand Redfield 6X scope and toppled many mule deer and antelope with it on the broken plains of Park County, Wyoming where I lived until 1973. But this is a fairly heavy rifle weight wise and I would not recommend it for a young hunter under say about 15.
NEF and H & R build fair quality single shot rifles for 270, 243, and 30-30. Stocks are easy to shorten, too.
Rossi offers a 243 in kid-sized single shot rifle. There are several video clips on YouTube that show this rifle in action.
Sherwood
