I am the customer that Paul talked to. He is absolutely correct in what he related. Those heavy arrows are twice as heavy as some others I was shooting at the same time. The Hammerheads also shot about a foot lower at 15 yards and were moving a lot slower. They did hit with exceptional authority and were moving the target around much more than my lighter arrows, especially with the 68 pound Shrew longbow. The tapered shafts make the AD arrows very spine tolerant, as has been reported by others. Paul built the heavy Hammerhead arrows for use with the Alaska Bowhunting Supply Ashby single bevel broadheads. I hope to put at least one of these arrows into the kill zone of a cape buffalo in a few weeks. These arrows have 100 grain brass inserts with 70 grains of additional weights that screw into the back of the insert. They also have the glue-in inserts and g-nocks in the rear. It is nice to have the easily replaceable nocks with the strong inserts since on the 15th shot with the arrows I did a partial Robin Hood and ruined a nock.
I have also shot the AD Traditionals and the AD Trad Lites, and all of them show great spine tolerance.