I confess that I came to the same conclusion as Dr. Ashby by the "blind hog picks up an acorn" approach. I shoot bow poundages in the high forties due to 3 shoulder arthroscopies and the simple fact that I'm not as young as I used to be. The obvious choices, 1916's and 2016's flew great with points in the 100-145 grain range, but I was less than impressed with their penetration. I killed deer, but pass throughs were not a given, even when no bone was encountered. Axis/Beman 500's with 175 grain heads were an improvement, but I still wasn't satisfied and wanted a heavier shaft. I got some 400's, which everyone knows is way too stiff for my set-up. I left them 30.5" long, with 100 grain inserts and 250 grain heads. Total arrow weight is now 680 grains and I thought that must be the ticket, as I'm blowing through deer like hot butter! Never considered nor checked the FOC until reading the article...24%! Yea, trajectory out past twenty yards isn't impressive, but I'm not shooting at anything outside that anyway! Thanks Doc, for proving that I'm smarter than I look!