I built a 10" .300bo pistol mainly for pigs, I don't hunt them anymore, but I will someday again. Although I have never used it, I made the decision based on the very knowledgeable members here.
I used a .223 mini14 with great success. I caught the AR bug and combined with periods of boredom I finally arrived at a 10.5" 5.56 pistol... really just wanted something obnoxious. Didn't really see the appeal to AR pistols; I had just wanted to try it. Turns out the AR pistol is a real hoot and could be shot fairly accurately to boot.
Well I re-evaluated the situation and my close up hunting style. Then I consulted the forum got lots of information here and other places. So, decided to build a 300bo upper. Nothing budget about this upper, at least by my standards, I'm itching to try it.