All of my calling rifles have bull barrels. I may, or may not need it, but it's a matter of personal preference. Embedded in my thick skull is the need to have a bull barrel in order to have an accurate rifle. I know this to not be necessarily true, however I do have a reason. FOr me, it's all a confidence level. It's the same reason I am not happy with a rifle that simply shoot MOA, and why I take so much time with load development. Again, it's all a confidence level. When I pull the trigger, I want no doubt in my mind that my rifle is capable of making whatever shot I am tryying to take. If I have a rifle that is a one whole shooter, when I pull the trigger, I will be much more relaxed, and confident in the shot. most of the time, that equals a downed animal. Now, if you get me out there with a rifle that shoots a 1" group, in my head I will not be as confident and will second guess my aim, elevation, all sorts of stuff, and I usually miss.
So, is a bull barrel necessary; absolutely not, but for me it is. And trust me, I wish I could build a rifle with a pencil barrel that makes one ragged whole, I just haven't done it yet. Hopefully someday I will.