Re: Air Rifle to improve shooting skill ???
I would chose the springer. I have a Beeman R1 I have had since the mid 80's. It flat out shoots and the recoil is helpful to me in that it doesn't just sit there after the trigger squeeze. I use mine to shoot gophers in the yard and I get really upset when I miss because I know what the gun is capable of. Misses are my fault.
It teaches great technique. The trigger is very smooth and the recoil teaches good follow through.
Get a good scope and you can simulate your long range set up. I had one of the 22 bullet traps with the spinners in it so you could see your results.
Bottom line is they are a lot of fun and great practice. Also great to
Teach kids safe handling and effective shooting.