Jim, I had only two choices of small shot the day I was at the gun store. I picked the smaller because I felt they would pack closer together and there would be less chance of vibration or ringing. The #6 looked to me like it was big enough to get too many spaces. I am flying by the seat of my pants here when I make choices like that, so don't rely too much on how I do it. Seemed to work though.............Bob
