Let's talk about powder density....

rwsmith · Jul 18, 2016

Are Accurate powders more dense than others? Their 1 lb. jug is smaller than a 1 lb jug of most anything else (except Vhitavuori). but the loads call for about a grain more than other powders and I seem to go through a lb of Accurate faster than a lb of Alliant powder???

Sevens · Jul 18, 2016

I'd say that Accurate is perhaps THE most dense powder, on average, available on the market. But then again, I'm a handgun guy and a handgun handloader, so my comments are pretty much contained to handgun.

As such, the powder is the cheap part of most any rounds I load. It's been quite a while since I considered a lighter charge weight/economy to be even a tiny part about choosing a handgun powder.

I'm a pretty good shopper, so I "save" money in other places, but I never worry about it when selecting a propellant.

Rule3 · Jul 18, 2016

You can not "generalize" powder density by one particular brand. Powders within any brand have different formulations or chemistry..Density will also vary by lot number and even what environment it is in. Just like flour, Bakers weigh" flour they do not use a measuring cup as humidity and altitude will vary the exact weight.

LEE has a chart of their measurements, but if you do the same with you sample of powder it may or may not be different.

Frequently Asked Questions
/vmd-explanation

http://leeprecision.com/cgi-data/instruct/VMD.pdf

Twoboxer · Jul 19, 2016

rwsmith said:
Are Accurate powders more dense than others?. . .

I agree with Rule3, but I still think the Lee VMD chart will give you a good "on average" approximation. Check it out.

A quick look shows Accurate powders occupy a smaller part of a CC per grain of powder than many pistol powders I know by name. If it holds true for the powders you are comparing, that would seem to make them more dense.

But since you are using volumes of powder that result in a given charge WEIGHT . . . if your charge target weights were the same for two powders, you should use up a pound of each equally fast, regardless of their bulk density.

fredj338 · Jul 19, 2016

In a word, yes. Very fine ball/spherical powders. Many other powders share sim density.

rwsmith · Jul 19, 2016

Of course I'm speaking....

Of course I'm speaking in general. The only Acc powder I've tried and looked at load for is Acc #7, but it always seem a grain or so heavier in the load tables besides coming in a small container.

I guess that could be an optical illusion.

I do know that 'Trail Boss" is intentionally less dense and bulky.

The shape may also affect how a powder 'packs'. Small ball powders pack without much space between the grains. When I worked with granulated carbon they used to 'trickle' the grind into a graduated cylinder to get it to pack to maximum in order to standardize the value of the density as closely as possible. We used to manufacture activated carbon from coal, which was heavier than the wood based stuff we later used. (And then there was coconut shell based product)

I can't afford Vihtavuori, though it's supposed to be great. Thanks to the shortages I have about 8 different pistol powders, mostly Alliant, Hodgdon, IMR and a couple pounds of Acc #7 which is really good for several applications, including soft shooting reduced loads in 9mm with 147 grain bullets.

Since powder is more available and a little cheaper than it was, I'm not as concerned about economy/load, but I was curious as to why the Accurate powders come in what appears smaller containers. What I do worry about is being able to keep enough powder on hand in case another shortage hits.

I have close to 20 lb of powder at home. I understand that I can only store more if it is contained in a one inch thick wood cabinet.

Leslie Sapp · Jul 19, 2016

I've attached a useful chart that compares powders by burn rate and density. I go to it often when trying to select a powder that will fill the case I'm using.

Rule3 · Jul 19, 2016

Leslie Sapp said:
I've attached a useful chart that compares powders by burn rate and density. I go to it often when trying to select a powder that will fill the case I'm using.

Thanks. That is good chart. I shows what "we" have been trying to emphasis (in other threads)"magnum" powders being not only slower burning but dense. They fill the cases up so it's less likely to have an oops and blow things up compared to FAST powders.

Clovishound · Jul 19, 2016

Well, as to the running through a pound of powder quickly, that will be a function of weight of the charges rather than density. It doesn't matter how fluffy say, 10 grains of a powder is, you load by weight, so you will get 700 rounds from a pound of powder. If the load calls for 9 grains, then you will get 777 rounds with just a little left over.

This is why fast powders like Titegroup are so economical. Compare a slow powder for H110 in .357 with a 158 grain jacketed. It calls for over 16 grains max. Titegroup calls for a little over 6 grains max. That is a huge difference in powder.

Rule3 · Jul 19, 2016

Clovishound said:
Well, as to the running through a pound of powder quickly, that will be a function of weight of the charges rather than density. It doesn't matter how fluffy say, 10 grains of a powder is, you load by weight, so you will get 700 rounds from a pound of powder. If the load calls for 9 grains, then you will get 777 rounds with just a little left over.

This is why fast powders like Titegroup are so economical. Compare a slow powder for H110 in .357 with a 158 grain jacketed. It calls for over 16 grains max. Titegroup calls for a little over 6 grains max. That is a huge difference in powder.

True but look at the performance.

Titegroup generates more pressure and LESS velocity.

Depends on what you want in a load. Plus the odds are greater for a new reloader to have bad things happen with such a fast powder in a magnum load.

Clovishound · Jul 19, 2016

I was not recommending the fast powders, merely using them as an example to explain the differences.

I have used Titegroup and Bullseye. They have their advantages as well as disadvantages. For .38 and .357, I much prefer slower powders like Universal. I really like 4227 in .357, but it costs a good bit more to load than Universal.

Wise_A · Jul 19, 2016

rwsmith said:
I can't afford Vihtavuori

The price of a powder isn't on the tag, it's in the charge weights. I consider some of the super-slow powders for .44 Magnum (2400 and such) to be very expensive because they require something like a 22-grain charge when something like Unique only demands 10.7-11 grains for a fairly stout load.

I'd love to buy some n310 or n320, but nobody wants to carry it locally, because everybody local thinks it's so expensive.

DWalt · Jul 19, 2016

The proper terminology is BULK density, which refers to granular materials, not solids or liquids. essentially the weight per unit volume, grams per cc, pounds per cubic foot, etc., of the granular material, depending upon what units you want to use. As noted, tables of bulk density for various propellants are readily available. The older editions of Handloader's Digest always had bulk density tables in them.

I use AA#5 for hot 9x23 Winchester loads as it is by far the best propellant for it, as its high bulk density (near the top of the list for pistol powders) allows the greatest mass of propellant in the relatively small-volume case. Ball powders always have higher bulk densities than granular powders, as the packing efficiency of balls (especially balls of mixed diameters) is much greater than sticks or flakes.

rwsmith · Jul 20, 2016

Great chart.....

Leslie Sapp said:
I've attached a useful chart that compares powders by burn rate and density. I go to it often when trying to select a powder that will fill the case I'm using.

That is a VERY useful chart. Good having that info in one place.

rwsmith · Jul 20, 2016

There are quite a few variables..

Rule3 said:
True but look at the performance.

Titegroup generates more pressure and LESS velocity.

Depends on what you want in a load. Plus the odds are greater for a new reloader to have bad things happen with such a fast powder in a magnum load.

It's not just 'peak' pressure but the shape of the entire curve as well as where the peak is from ignition to the time the bullet leaves the barrel. I'd love to delve into internal ballistics more but it's a huge can of worms.

rwsmith · Jul 20, 2016

At $10/lb more.....

Wise_A said:
The price of a powder isn't on the tag, it's in the charge weights. I consider some of the super-slow powders for .44 Magnum (2400 and such) to be very expensive because they require something like a 22-grain charge when something like Unique only demands 10.7-11 grains for a fairly stout load.

I'd love to buy some n310 or n320, but nobody wants to carry it locally, because everybody local thinks it's so expensive.

To a poor guy like me that's substantial.

It's premium stuff, but I don't really need premium stuff when the regular priced powders go 'bang' and shoot a bullet out of the end of the barrel. It's kinda like not developing a taste for expensive scotch or coffee. I do, however, see that some of the Vihtavuori line give top performance in some loads. That would be worth the extra cost if used sparingly.

I see it around here occasionally, but usually it's only one or two lbs at any one time. Not much of a selection.

rwsmith · Jul 20, 2016

Thanks.....

DWalt said:
The proper terminology is BULK density, which refers to granular materials, not solids or liquids. essentially the weight per unit volume, grams per cc, pounds per cubic foot, etc., of the granular material, depending upon what units you want to use. As noted, tables of bulk density for various propellants are readily available. The older editions of Handloader's Digest always had bulk density tables in them.

I use AA#5 for hot 9x23 Winchester loads as it is by far the best propellant for it, as its high bulk density (near the top of the list for pistol powders) allows the greatest mass of propellant in the relatively small-volume case. Ball powders always have higher bulk densities than granular powders, as the packing efficiency of balls (especially balls of mixed diameters) is much greater than sticks or flakes.

...for the proper term. Should have used that at the beginning of the thread. Oh well......

rwsmith · Jul 20, 2016

True, but I've noticed......

Twoboxer said:
I agree with Rule3, but I still think the Lee VMD chart will give you a good "on average" approximation. Check it out.

A quick look shows Accurate powders occupy a smaller part of a CC per grain of powder than many pistol powders I know by name. If it holds true for the powders you are comparing, that would seem to make them more dense.

But since you are using volumes of powder that result in a given charge WEIGHT . . . if your charge target weights were the same for two powders, you should use up a pound of each equally fast, regardless of their bulk density.

I have the impression that #7 is denser AND takes bigger charge weights. The pound of lead vs. a pound of feathers thing applies here, though not so extreme.

Here's a story that has nothing to do with anything, but it's a good one.

Someone discovered that Black Widow webs had a huge price/lb in the world market for cross hairs in optical equipment (i.e. rifle scopes, since this is a gun site) and considered getting into the supply business. The problem was that the entire world supply of webs for a year was about.... one pound.

BUFF · Jul 20, 2016

Powder manufacturers, like most makers of any product, like to buy stuff in bulk. I have notices that, pretty often, all of a powder maker's products of the same weight will be in the same size container, but when you open a new one, they are filled to different levels. Same weight of contents but take up different amounts of space.

rwsmith · Jul 20, 2016

Ah.....

BUFF said:
Powder manufacturers, like most makers of any product, like to buy stuff in bulk. I have notices that, pretty often, all of a powder maker's products of the same weight will be in the same size container, but when you open a new one, they are filled to different levels. Same weight of contents but take up different amounts of space.

...very observant.

Let's talk about powder density....

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