Try Dunn’s Supply on the internet. They are down in Grand Junction Tennessee. That is the home of the National Championship (FDSB). They were the best, but not cheap, suply house for trial equipment when I was running dogs. I was looking at the AFTCA website the other day and saw that guns w/ un-plugged barrels were no longer allowed in AFTCA championships so I’m not sure if there is the same demand as before.
I always used a single shot shot gun as my gun to fire over a point. I carried a cheap 20 guage in my scabbard. I liked the way the dogs would stay “bulled up” anticipating a kill. The gun was also a training aid.