POWDER WEIGHT VS VOLUME

[normanlclark]

Perhaps this is an old and simple question, but I am an old and simple man; I have several powder measures, both by volume and by weight. Using a small test tube from my high school chemistry set, I find that a powder of the same exact weight is not always the same exact volume, and obviously visa versa. So which makes a bigger BANG, more weight or volume? This may be minutia, but I'm just curious.

 

[oldman10mm]

a recent related thread.

http://smith-wessonforum.com/reloading/482228-lets-talk-about-powder-density.html

 

[Twoboxer]

Taking two samples of the "same" powder:

If two samples have the same volume but different weights, the heavier one will.

If two samples have the same weight but different volumes, neither will.

 

[Clovishound]

I have heard it said that volume is a better indicator. I also see that ALL the manufacturers list their max charges by WEIGHT.

Yes, I know that Lee lists a volume in their manual. I believe that this is to make choosing a setting or disc on your powder measure easier. They state in their powder measure instructions that max charges must be weighed.

So, regardless of whether weight or volume determines the amount of energy released, I will do all my quality control by weight.

 

[OKFC05]

All chemical reactions are based on the weight of the reactants, or number of atoms that participate in the reaction (MOLES).
The volume varies with several factors including humidity and physical handling.
That is why serious bakers weigh the amount of flour and do not rely on volume measurement, which varies from bath to batch and day to day with humidity. And it is why all gunpowder recipes are listed by weight.

OF A SPECIFIC POWDER, more weight makes a bigger bang, given the same containment. With no containment, smokeless powder just burns like crazy, and does not go bang. The chemical composition of smokeless powder is about the same as the movie film from 100 years ago, nitrocellulose. Old movie film is very dangerous to store because it burns so well.

 

[fredj338]

We do all load dev by weight because that is what the powder manuf use. Its also far more precise. Volume measuring requires a good technique &/or exc equip to get even close to 1/10gr accuracy with most powders. With course stick powders, you almost have to weigh them to get even within 3/10gr.
Bang for your buck, depends on powder. Something like Trailboss has a huge volume per weight., even though burn rate is near TightGroup, very small volume per weight. TB could never be double charged, TG could easily be even triple charged in a large case. Use your scale to set your volume measure, done. Its really that simple.

 

[normanlclark]

Thank you all for your answers! Being never in a rush, I always weigh every charge even when I use the Lee disks. After I finish a batch, I weigh every completed cartridge, which at least will tell me if there is a double charge, or if I missed one.

Thanks again.

 

[Rule3]

Hey

That is why serious bakers weigh the amount of flour and do not rely on volume measurement, which varies from bath to batch and day to day with humidity.

The bakers line is mine!

You have all the Chemistry and Statistics stuff.

 

[gregintenn]

We load cartridges with powder by weight. How many of us loads a muzzleloader by weight?

Consistency seems to be a bigger factor in accuracy than which of these one uses to achieve it.

 

[rwsmith]

MASS

In chemical reactions it the the mass of the constituents that count foremost. If volumes, densities, etc are standardized, then volume would be a good measure, but the mass is still primary.
Anyway, the closest association we can easily make to mass is by weight, therefore we use scales for the most accurate charge.

Even powder measures that are given in volume are usually a small enough amount that slight differences in density are inconsequential (besides the amount of powder being figured conservatively) however, even volumetric measures should be verified by a scale, especially when approaching max loads.

PS In chemistry, a standardized volume is a 'mole' which is a molecular volume tied directly to the number of molecules using Avogadro's number , which will tell you what the mass of the reactant is.

UPDATE: LOL OKFCO5......I think we are in agreement! As usual, though, you said it in less words.

 

[fredj338]

Thank you all for your answers! Being never in a rush, I always weigh every charge even when I use the Lee disks. After I finish a batch, I weigh every completed cartridge, which at least will tell me if there is a double charge, or if I missed one.

Thanks again.

Save yourself some time. Weighing completed pistol rds with small charges of fast powder tells you nothing. In a 45acp, case & bullet variations can easily add up to 5gr+. if you are loading medium burners like unique, can't even get a double in w/o it almost spilling out.

 

[fredj338]

We load cartridges with powder by weight. How many of us loads a muzzleloader by weight?

Consistency seems to be a bigger factor in accuracy than which of these one uses to achieve it.

Black powder is totally diff. You load black powder by volume, even in cartridges, the actual amount is not a huge deal. You are compressing the BP in a muzzle loader & in a cartridge, same thing, fill the case, place the bullet, or fill the case 3/4, place an over powder wad & compress. Actual powder weight in BP, not as important.

 

[SMSgt]

" I find that a powder of the same exact weight is not always the same exact volume, and obviously visa versa. "

Gee, Mr. Wizard, which has more volume, a pound of lead or a pound of feathers?

If the data says load 5.0 grains of powder "X," load 5.0 grains of "X."

Volume was okay in black powder days, not so good in smokeless loads.

 

[fredj338]

" I find that a powder of the same exact weight is not always the same exact volume, and obviously visa versa. "

Gee, Mr. Wizard, which has more volume, a pound of lead or a pound of feathers?

If the data says load 5.0 grains of powder "X," load 5.0 grains of "X."

Volume was okay in black powder days, not so good in smokeless loads.

The vast majority of handgun reloaders use a good volume measure set with a good scale. Nothing wrong with that. I shoot 1000rds a month. I would not want to be weighing 1000 charges.

 

[normanlclark]

" I find that a powder of the same exact weight is not always the same exact volume, and obviously visa versa. "

Gee, Mr. Wizard, which has more volume, a pound of lead or a pound of feathers?

If the data says load 5.0 grains of powder "X," load 5.0 grains of "X."

Volume was okay in black powder days, not so good in smokeless loads.

Not sure why there always has to be a smart ***. I am weighing and checking volume of Winchester 231. You go ahead and weigh your pound feathers and lead.

 

[Wise_A]

It's actually kinda handy to know for quickly setting up a volume dispenser (charge bar, the Lee disks and drums, etc). I actually add that information to my ammo labels when I'm playing around with new loads.

 

[Engineer1911]

Accuracy-- safely load the case

While all of this is very interesting, I firmly believe that an accurate "Close Enough" will get the job done.

No matter how much statistics you use, no matter how many measuring tools you use, there is still that bad part that got to the customer.

Maybe that is why we have so many great groups with just ONE flyer.