air gun hunting

[Catfish]

I seen just what your after while I was in Alaska. It was a 9 mm air gun and put a cast 129 gr. bullet throught a 2 x 4 and into the second. They were not cheap and you use a high presure hand pump or a pump that they use for scuba tanks to pump it up. I forget who made it, but you might gogle 9 mm air gun and see what happens.