thank you all, and Jackcrafty in particuar ...
I understand why you are saying, but eyeballing is going to have to do ... and my shoots are not 100% straight. I will have to work on making them straighter and eyeballing to 1/64 the best that I can ... maybe a tiny level ... If I feel comfortable with 2lbs after some tests, I will go to that for more accuacy.
Ultimately my goal is to have arrows I can have confidence in, so that I can spot errors in my perfomance. This will get me in better range than the unspined unweighed floating (read inconsistant at 24 inche arrows) anchor that I have been working with. If I have a set that are the same at 20 or 21 inches (all the same, Im still debating length) of 350 grain and 30-35 lbs (again the same as much as possible), Ill have a basis to judge my ability with minimization of arrow related errors.
I am sure they will not be 100% the same, but if I get consistancy, then maybe I can copy the best of the lot to tune.