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!!!