Found a
site that lists load data for Black Powder Shotgun Shells. But the data is for Black Powder ffg and is by weight.
For example use 2.5 drams of BP for a 12 gauge shell along with 1 ounce of shot.
When I do the
conversion to grains:
2.5 drams = 68.359375 grains.
But what if I wanted to load Pyrodex RS instead of BP?
So I found another
formula that says 100grs of BP ffg by weight is equal to 72.5grs of Pyrodex RS by weight.
OR
100grs of BP ffg by weight is equal to 63.9grs of Pyrodex Select by weight.
AND
100 grains of Black Powder ffg by Volume = 101.3 grains of Black Poder ffg by Weight
I DO NOT KNOW IF THE ABOVE CONVERSIONS ARE SCIENTIFICALLY ACCURATE, HENCE MY POST. I realize anyone with a word processor and a site can post whatever data they want; accurate or not.
If the above conversions are correct, then 2.5 drams by weight of BP = 68.359375 grains by weight of Black Powder = 67.5 grains of Black Powder by volume. 67.5 grins of Black Powder ffg by volume = 67.5 grins of Pyrodex RS by volume 67.5 grins of Pyrodex RS by volume * .725 = 48.93 of Pyrodex RS by weight.
So I emailed Hodgdon's to check my math and I got the big KABASH!!!! They said to use 50grs of Pyrodex by volume for that load. Didn't specify which Pyrodex.
Before you say why do the conversion, just load it by volume. Remember the original load data started out by weight.
Ok, so if you were presented with load data for a BPCR Shot Shell; its was by weight in DRAMS (not volume); and you wanted to shoot Pyrodex (you pick RS or Select), how would you do the conversion?
How did Hodgdon's get 50 grains by volume for a 12ga using 1 ounce of shot?
HaYen
