I made an unsettling discovery yesterday while checking my "zero" at 20 in prep for shooting my target for the match. I had hits right on, and some almost 2" low. I have a primitive balance beam "scale" made out of a 4' strip of oak w/ a string at eack end w/ alligator clip and one on opposite side to hang it w/. I thought all my LII's were close in weight. WRONG!!
By using a dollar bill, [15.3 gr.] I found some were $1.50 heavy. LOL But, that's over 23 gr.

I ordered a $39.00 digital scale last night, planning on evening them up via putting 8-32 set screws in nock ends w/ loc-tite

BTW scale ended up around $200 as I "needed" a few other things for turkey hunting!!!

Hey Dan, you will also want to consider using brass and don't forget to keep in mind that you want some FOC (forward weight of center) so that they are front heavy. I just use one of my balance beam scales that I use for gun powder.