Art, all good points, especially about having identical momentum and changing KE, I wondered about that also. To his credit, many of the variables you mention he did take into consideration. He shot each arrow ten times and took an average of the ten. Every shot was through a chronograph at the exact same distance. I believe the same bow was used and each arrow tuned to the bow before testing. For the momentum I believe it was 300gr and 600gr, used aluminum, same length one was 22 something the other 22 also but thicker walled so the arrows would be the same diameter. Gees, I can' t remember all of the gory details. I' ll look tonight and get all the stats, you should buy a copy so you can read it. Still no statistics though, is it signifigant, it is very easy to look at raw numbers and draw conclusions but you can' t draw any real conclusions without proving statistical signifigance. Like you said Art, they publish a bunch of numbers people will take as gospel and truthfully no one knows if they mean anything at all.