One of the more recent developments is the popularity of the 13.5" twist barrel. I believe that it was Lester Bruno that was responsible. He discovered that with his 00 BT bullets (that I believe are made with an .825 length jacket) that that twist really works well. Some time back, I seem to remember that one of the big names in the history of benchrest said that he thought that they obviously would work, that bullets made with .825 jackets might be a little longer than ideal for a 14" twist. Another way to get to this relationship is to use a bullet that is slightly shorter, and I believe that my late friend Del Bishop was an early adopter when J4 started making .790 jackets. Going forward a number of years, Berger has done a lot of design and testing before adopting a new design that is their Column bullet, and I don't think that it is accidental that it is made with a .790 jacket. I am sure that they recognize that the 14" twist is the most common, and have optimized their design for that.