Hi Tyson,
I think we have touched on this before, I know I suggested it to jon once when he was wanting some weight in a loco with little place to put it!
The powder is much heavier than powdered lead. You can't melt and cast this stuff like lead, 'cause it melts at 3387 Celsius,
according to Corbin's table. So if you could cast a weight to fit your space, you may be better off with lead. Or you can pour in the tungsten powder and glue it, and get about the same density as solid lead, I think.
It's an interesting project, anyway