Thought this might be of interest. I have it posted at the computer as well as at my loading bench. It's handy for cross referencing as well as for loading shells, having an easy meausre for striken loads of BP.

50gr. = 5/8oz.
60gr. = 3/4oz.
70gr. = 1oz
80gr. = 1 1/8oz
90gr. = 1 1/4oz
100gr.=1 3/8oz.
110gr.=1 1/2oz.
120gr.=1 5/8oz

Another is X gr. measure = Y drams of powder. Using 27.3gr. = 1 dram. These are close, not exact.

55gr. = 2
62gr. = 2 1/2
68gr. = 2 1/2
75gr. = 2 3/4
82gr. = 3
89gr. = 3 1/4
96gr. = 3 1/2
102gr. = 3 3/4
109gr. = 4
116gr. = 4 1/4
123gr. = 4 1/2
130gr. = 4 3/4
136gr. = 5
143gr. = 5 1/4
150gr. = 5 1/2
146gr. = 5 3/4
164gr. = 6