Mine have 2 check, 20 and 50g but I wan to check the scale thru the range specially around the 60 gr area where more of my loads are. Every time I have used the checks that came with it the 20g is very consistent but the 50g is not. However, both are way over my 60gr powder average.
I think my idea should work, I am just making sure there if there is a real reason why you must use those factory made checks AND also see where will be the best place to take those "home made" check weights to get an accurate number...