Measuring black powder by weight or volume?

[Gary Van Kauwenbergh, 101]

Here’s an interesting article discussing measuring black powder by weight vs. volume. I agree with the author’s logic, but don’t think weighing by volume is quite as ‘sinful’ as he seems think it is.

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

[Maillemaker]

I weight all my competition cartrige charges with a scale.

A volumetric measure can get you close, as the author notes. But it is easy to see why volume is not consistent. Fill up a measurer to the top, then tap it on the table a couple of times. The grains will settle and compact, and now the measurer is not "full" anymore.

If you consistenly handle and use a volume charger, then you can get pretty consistent drops. Especially if it is mechanical in nature and thus highly repeatable.

But ultimately, it's the weight that matters. Whether you arrive at that with a scale, a volume, or plucking out individual grains with tweezers.

Steve

[Steve Light, 0026V]

I wrote an article for the Jan-Mar 2005 issue of The Skirmish Line that explains why volume is more critical than weight when changing powder lots. You can weigh powder anyway you want to with a specific powder lot as long as you do it the same for each load. However, when you change powder lots, you need to be careful if you load your charges using the same measure of weight because the performance
of the load can change for many reasons, the number of granules being one of the most important.

Black powder is a mechanical mixture of three major ingredients, charcoal, sulfur and Potassium Nitrate.
a change in the shooting performance can occur if any one or all ingredients between powder lots change.
Another factor is the weight of the charge per equal volume can change that can result in the number of granules increasing or decreasing. When this happens, the performance of the load can be significant. Powder does not explode but burns from one powder granule to the next. The closer the granules, the faster the burn rate with resultant higher pressure. Why do you think 3F powder is hotter than 1F powder, if all other factors are the same.

The bottom line is when changing powder lots do not automatically use the same weight of the powder charge that you used in the older powder lot. Also, check the volume. It you use a hand powder dipper, check to see if the level of the powder has changed. If it does, then you can expect a change in your shot group. Since you can't check to determine if the charcoal is richer or if the percentage of the
ingredients have changed, make sure to test fire your weapon when you change powder lots to see if
the shot group will change. You're lucky if it doesn't change and you have to return to re-sighting
in the weapon.

Recommend Randy Wakeman read my article

Merry Christmas

Steve Light, Washington Blue Rifles