When I was about 11 my dad would not buy me a bb gun. When I bugged him enough he told me to get something more accurate and a bit more powerful. My friend had a Sheridan air rifle that shot pellets(single shot) that you could pump up to 15 times for max power on each shot. My dad was impressed with this gun so he bought me one, stating that "you'll get tired of pumping and eventually learn to make the first shot count." That was 34 years ago and I still own that air rifle and it still shoots great! The only work I did to it was refinish the stock about 20 years ago to remove the scratches it received from my pursuit of birds and chipmunks as a kid. I have used it recently to shoot a woodchuck that was raiding my garden, since gunshots tend to scare my neighbors.
I STRONGLY recommend this air rifle as a precursor to actual powder charged bullets.