Ditto to what both Jesse and Brock both said! When I shot the aluminum orange xx75's 2018/2117's back in the 80's I did the same thing that Brock mentioned about heating and rotating the insert while still hot to get the perfect spin.
Whelp, I cleaned the blood off the arrow I shot my buck with last year and removed the muzzy and screwed on the SS magnum 100 and got an unbelievable true perfect spin. Then went and shot one shot at 20 yards and got this:
Then stepped back to 30 yards and shot this:
Then after three shots at 40 and a very small sight adjustment I got this:
All I can say is WOW! What great flight I got with this head! I am going to try and kill a deer with this same arrow I did it with last season. I will be swapping this same head with 4 other arrows and hopefully I'll get the same results so I'll have 5 in the quiver when I take to the woods here in about 2 weeks.
I'm glad I gave these heads a try and will be looking forward to seeing how they perform in the field. Thanks to all those who suggested me and others to give them a try!