If you can hit a rabbit being chased by dogs with a .22 then go try out for Top Shot's next season. I run beagles and usually about 20 a time. Any gauge shotgun will suffice but a 20 or 410 will save your arms from getting tired. I recommend you research running dogs and find someone local who does it. The best thing you can do is put your pup in a pack of already trained beagles and natural instinct will take over. There so much when it comes to running dogs we'd be writing a novel trying to tell you everything so my main advice is find a local hunting club that runs dogs an try to get your foot in the door.