I am not an expert in any way, but the following link is to a downloadable PDF book that I have used to answer some of my "why is my pistol leading" questions. Great reference material and it is free.Ok, I think y'all have convinced me lol. With that said, at how many fps do you start to see them leading the barrel?
Terry
http://www.lasc.us/Fryxell_Book_Contents.htm