I've participated in lots of our discussions regarding tuning carbon's and finally got success with mine. What I had left over was a bunch of Carbon Express Terminator Hunter's in 4560 and 6075 weights. They were of various lengths from 27-30" and had numerous different inserts (aluminum) and ones that I had cut down from 100 grain brass.
I also had a bunch of two blade broadheads, mostly Zwickey and Magnus. These also varied in weight from 117 to 175 grains.
I borrowed a friends electronic grain scale and weighed and marked everything.
By moving inserts, putting 100 grain brass up front and putting the very heavy broadheads to use, I have come up with great flight for a lot of expensive shafts that I had previously figured for junk.
I know I would never have thought of it without all the discussions I've read here. Thanks.