Volume or weight?

[NAA_Silent]

I want to use up some of my Pyrodex P in my Hawkens 50 rather than buy more American Pioneer. I have 2 cans of Pyrodex P, and I'm nearing my legal limit for powder stores. I saved the tubes from my last run of AP to reload, and I've noticed that 65 grains, by weight, of Pyrodex P fills the tube to about the same point that 100 grains of AP fills the tube. Something just doesn't seem right to me. Am I suppose to be using volume, or weight? I use a marked brass measure with my pistols.

 

[mooman76]

By volume. It even states on the can that you get 25% more per #, that's because it is lighter but equivalent to BP by volume.

 

[Rat Trapper]

Go with by volume. If you want to do it by weight you must first take a powder measure and pour a charge and then put it on your reloading scale to check it for weight. Do several this way and take an average of what your volume charge weights. Once you have an average you can weigh your charges if you want.

If you use those plastic tubes as your powder measure you will end up with a by volume of 100 grains.

 

[NAA_Silent]

Thank you gentlemen. I knew something wasn't quite right. As a reloader, when I think grains, I always think weight.

 

[rafterob]

I think you will find 55-60 grains by volume of Pyro P will be a good load in that rifle.

 

[Zonie]

Pyrodex weighs about 30 percent less than real black powder per cc but it has about the same energy per cc.

Put another way 70 grains by weight of Pyrodex has the same volume as and power as 100 grains of real black powder.

It was designed to be measured by volume because that is the method most muzzleloaders use when they load their gun.

 

[crockett]

NAA Silent:the density of pyrodex and similar substitutes varies from batch to batch so the manufacturers add a filler so that each batch produced is equal by VOLUME and not weight. To have equal charges you must measure by volume- even with powder from the same manufacturer.

 

[NAA_Silent]

I took a couple shell casings and the chart from one of the other sub forums here and made a couple measures. One at 50 grains, and one at 65. I double checked them using my brass measure, and they seem to juive just fine. My 30-06 casing came in at 65 grains, and I trimmed down the 243 Winchester casing to hold 50 grains by volume. Made a few tubes of Pyrodex P using those measures. I'll try them out next range trip and see how they do.

 

[crockett]

I should add that there is a handful of modern cartridge benchrest shooters that go with volume rather than weight and they do very well. I forget their argument but I think it pertains to the pressure in the case changing with volume more and with changes in weight. IAE the point is these benchrest shooters that use volume do very well so there is no reason to think you are being handicapped in any way by going with volume versus weight.
About a year ago MUZZLE BLASTS magazine started a series featuring competitive shooters and how they loaded and I was sort of surprized that a lot just used a standard measure with the top that strikes off- I thought maybe they would be using drop tubes and all sorts of things.

 

[M. De Land]

The reason is because black powder potency can change from lot to lot so volume in a brass case will often change which directly effects powder column height and compression which in turn effects burning rate and accuracy. I should add most of them do both, that is, they also weigh after dropping a charge from a powder measure.
The other thing done for compaction of powder and more consistent powder column heights, is drop tube the powder. Slug gun shooters do the same thing into their muzzle loaders.
I don't weight any more,just use a muzzle loading powder measure and can see no difference in accuracy.
Black powder cartridge shooters will very often buy a whole case or two of the same lot of powder. Most of us use Swiss as it seems to be the most consistent and dense powder available.
I know of one shooter that says he goes through over two cases a year. That's over 50 pounds! MD

 

[M. De Land]

You can have case lots of black powder delivered to your door step still, even now days. MD

 

[NAA_Silent]

Not here. We are limited too 1 pound of black powder maximum. Total BS if you ask me. I'm going to go get a pound of Goex FF this weekend.

 

[rafterob]

I think maybe I'd dig 24 holes in my yard for the rest of the case :grin:

 

[Rat Trapper]

I'd just get the case and not tell any of those liberals I had it. Keep it out in the garage in a good storage box. How are they going to know ya have it if you don't tell anyone??

 

[cynthialee]

I'd just get the case and not tell any of those liberals I had it. Keep it out in the garage in a good storage box. How are they going to know ya have it if you don't tell anyone??

bad idea!

It may be a stupid law, but it is what it is.

A better fix may be to secure a pound of powder for each resident of the home. Each pound separate from the other cans in separate rooms, and labeled as to the owner.
Just a thought, I don't know the legalities. I am just guessing.