Robert,
There is any number of things you can do to arrive at perfect arrow flight with bare shafts. Different field point weight is only one variable. Try brass inserts to increase the FOC (both 50 & 100 gr.)of the bare shaft, which is in effect, just point weight any way. Tuning your bow differently can have a profound effect, specifically brace height, but brace coupled with nock height variation and different point/insert weights are a lot of variables to work with, not to mention your best shooting technique. Building out the strike plate or making your bow more center shot is another way of affecting a shafts spine relative to that bow, hence arrow recovery etc. Keep in mind changing one thing may reset the whole set of variables. As always with tuning, change only one variable at a time. I have played with CX Heritage 150’s and found them to be difficult to bare shaft tune, they seemed weak (relative statement) in spine and I had to go much lighter in tip weight than I otherwise would. Bare shaft tuning will also accentuate all your worst habits, so you’ll have to use your best technique to give it a fair shake (already mentioned). When all else fails, go outside the realm of what you think should work, it never ceases to amaze me as to what unconventional combinations actually work for bare shaft tuning. Also despite all the aforementioned, some shafts will just not work for you, through a given bow…try a different shaft, before you are totally discouraged. Also what Moose eye says is true, fletch will correct for “not so perfect bare shaft tuning”, but there is nothing like laser straight bare shaft flight for efficiency and confidence, IMO, fletch is just icing. Keep trying, I have found that eventually I can get just about any shaft ,within reasonable spine, to fly w/o fletch. It’s fun and a great learning exercise. Call if you’d like to talk more about it. 608.798.1103
Kris