ORIGINAL: Paul L Mohr
Actually you shouldn't weigh black powder or it's replacements like pyrodex, clean shot, or 777. You should measure them by volume, not weight, it's more accurate. The weight of these powders can change with temprature and humidity.
Actually temperature alone will not affect weight. Temperature
could affect volume measurements, but I've got no evidence if it does or not. Humidity can affect weight measurements as it adds mass to the powder (the mass of the water). If you keep your powder properly sealed you should not have any problem. I actually ziplock my bottles of powder when I'm not measuring. I also ziplock any quantity of premeasured powder. I use some of the vials (or similar ones at least) like what UC has posted the link to in similar containers for convienance which I also ziplock to keep moisture out. I'm a little obsessive about it.
Measure 100 grns by volume and then put it on a scale, I bet it's not the same.
Nope, they're not. Blackpowder is closest, but not perfect. The key to weighed charges, is weighing a
thrown charge. For example, 100 gr. of 777 by volume equals 80 gr by weight. To duplicate, you simply weigh out 80 gr. on your scale. I have the wieght/volume numbers all wrote down so I do not forget the conversion.
And if you work up a load during the summer, then weigh out some charges in the winter you may get some different loads. Unless you pre weigh them in a controlled inviornment. At any rate you should check the volume weight to the measured weight to make sure they are close. This would keep you from having an accidental over charge.
I still use my volume measurer when weighing charges. I've got it set to throw just under what I want to get. I then trickle the last few grains onto the scale.
smokeless powder is not the same, it can be measured by weight.
So can blackpowder or the subs as I've illustrated.