Ah, shoot, Smoke, you tracked me down.
I'm sayin' the same thing here. Load your measure to 40 gr BP, dump it in the scale, see if it is 40 gr. If it says 50 gr, you got a problem with your meaure, and you're saying, Man, 40 gr really lets out a bellow and a kick.
If it's 30 gr, you got a problem with your measure, and you say, Man, 40 gr is the pleasantest load in the 58 Rem, no kick, shoots to POA-POI.
All BP is measured by weight, then the weight converted to a volume for field reloading. We're shooting BP, here, another grain or 10 isn't gonna blow up a gun. A grain or 2 WILL blow up a centerfire cartridge gun. Go to the 44 Mag loads with Red Dot. I used to shoot a lot of shotgun, have a coffecan full left, been loading 44 Mag with it. Like 9.6 gr. 10 grs, possible catastrophy. It ain't the same stuff.
After you weigh out that 40 gr BP and set your VOLUME measure to hold just that much, then go ahead and fill it with Pyrodex, a VOLUME equivalent, it's OK, won't break your gun nor your head nor hands.
I'm gettin' tired of trying to explain this. It seems so reasonable and apparent.
A cubic inch weighs this much of this, and a cubic inch of something with the same destructive capacity will do the same, but a cubic inch of something more volatile has to be adjusted downward.
I give up,