Blackpowder grains vs. smokeless powder grains

[hunterofelk]

I am just learning the ins and outs of blackpowder shooting.  I am experienced with smokeless reloading.  I have a TC U-view Powder Measure and I wanted to test the accuracy of the increments on the tool.  I weighed out 90 grains on my RCBS powder measure and completely filled the cylinder of the measuring tool which is the 125 gr increment.  This powder is Pyrodex.  The info of Hodgen's web site says all their loads are measured by volume, but they list everything in grs.  This statement has got me confused.  Hodgen also says Pyrodex is 70% less in weight compared to blackpowder.  So what they are saying is Pyrodex poured to the level of the 80 grain increment will equal 80 grains weight of blackpowder in energy?  In weight, 56 grains of Pyrodex measured on my scale will equal the energy generated by 80 grains of blackpowder?

[Jason]

I'm pretty sure that smokeless powder is measured by weight and blackpowder is measured by volume.

[JimmyHoffa]

I'm pretty sure that smokeless powder is measured by weight and blackpowder is measured by volume.

[bobcat]

I think it's a good idea to work up the load for your muzzleloader just like you would when you reload modern firearm cartridges. Weigh the charges by weight on a scale and when you get your hunting load dialed in, you can check it in your muzzleloader powder measure, which measures by volume, not weight, and only gives an approximation of the actual weight.

Here's an interesting article by Randy Wakeman on the subject:

http://www.chuckhawks.com/blackpowder_volumetric.htm

[johnsc6]

I'm pretty sure that smokeless powder is measured by weight and blackpowder is measured by volume.