This is a very interesting and informative chart my friend Wayne Stormer came up with.
In this case, we'll look at the conversion of Goex FFg to Goex FFFg and vice versa making our measurements in volume of grains. We will see the conversion of them according to the two thoughts of 56% and 75% used by many when going from Goex FFg to FFFg etc. All numbers were rounded up and down.
GOEX FFg to FFFg at the 56% proposed rule of thought
50 gr FFg = 28 gr FFFg
60 gr FFg = 34 gr FFFg
70 gr FFg = 39 gr FFFg
80 gr FFg = 45 gr FFFg
90 gr FFg = 50 gr FFFg
100 gr FFg = 56 gr FFFg
110 gr FFg = 62 gr FFFg
125 gr FFg = 70 gr FFFg
GOEX FFg to FFFg at the 75% proposed rule of thought
50 gr FFg = 38 gr FFFg
60 gr FFg = 45 gr FFFg
70 gr FFg = 53 gr FFFg
80 gr FFg = 60 gr FFFg
90 gr FFg = 68 gr FFFg
100 gr FFg = 75 gr FFFg
110 gr FFg = 83 gr FFFg
125 gr FFg = 94 gr FFFg
GOEX FFFg to FFg
30 gr FFFg = 54 gr FFg (at 56%), 40 gr FFg (at 75%)
40 gr FFFg = 71 gr FFg (56%), 53 gr FFg (75%)
50 gr FFFg = 89 gr FFg (56%), 67 gr FFg (75%)
60 gr FFFg = 107 gr FFg (56%), 80 gr FFg (75%)
70 gr FFFg = 125 gr FFg (56%), 93 gr FFg (75%)
80 gr FFFg = 143 gr FFg (56%), 107 gr FFg (75%)
90 gr FFFg = 161 gr FFg (56%), 120 gr FFg (75%)
100 gr FFFg = 179 gr FFg (56%), 133 gr FFg (75%)
110 gr FFFg = 196 gr FFg (56%), 147 gr FFg (75%)
Then there is the differences in the mesh sizes, material components, quality and strengths of the different black powders and black powder substitutes. One must know and understand the differences and pay attention to the math for converting and using such things to avoid potential trouble.