You keep talking about hitting 50 in the head at 50yds. Your not going to hit the bird with 50 in the head using 5's. And even if your gun will put let's say 60 pellets in the 10" at 50yds with the 5's, that's like saying about 50/50 on your chances of killing the bird. You may kill one 3 times in a roll, and the next 3 you won't. I like the 100 in the 10" that way you know there won't be any surprises.