It' s a pretty simple process.........screw in a broadhead and on a smooth surface (like the back of a bow case etc.) stand the arrow up and spin it gently. if you see any wobble try the head in the rest of the arrows to see if you find one that it spins true on. If you can' t find one then you might have a problem with a bent ferrule on that head. Keep mixing and matching heads and arrows until you find as many as you can to spin true........the rest might be a matter of badly aligned inserts or like I said damaged or bent ferrules on a particular head, or in the case of aluminum arrows maybe a bent shaft.

And don' t go spinning the head like a madman or it might hop out of your hand and take somebody out!! []
You' ll know a good spin when you see it.......absolutely no wobble, just a pure even spin straight to the tip.