mshane,
Don't bother bare shafting them. (it took 10 years to believe this). You could actually be getting opposite readings. My current set up is a full length AT trad heavy wood grain with a 175 gr head and factory insert. The are working very well but would indeed show stiff if I bare shaft them.
I read a post by one of the gurus, maybe Rick Barbee or one of those guys. Who did a slow motion test on them and figured out they were recovering from paradox so quickly that they snapped themselves the opposite that he was getting reverse bare shaft reading.
Broadhead tune them to hit the same as your target points. You may need to do the opposite of what you know about tuning. Example - decrease weight when they show stiff with broad heads. Sounds all wrong but don't fight it, try it!
Also the modern AD trads are stiffer than those real old black ones. The original AD trad heavies were perfect spined for almost any hunting weight bow. Now they are little stiffer, mostly they do still work great and are my only carbon arrow but those softer ones were awesome. Once you get the point weight right they will tolerate a lot of variables and still fly perfect and hit the mark.
Mine are working great. I always use the wood grain because I like to see the arrow in my sight picture. In low light you can't see the black ones.
I like my AD trads and wood arrows to be interchangeable. And they are except the carbon is a little longer than the wood. So I played around with a shorter AD trad lite today. Those work too!
Tedd