Powder - Volume to Weight

Well, it was pouring like heck here today and boredom has set in. I remember a post on one of the forums about the accuracy of the graduation marks on BH209 tube - how accurate they might be if used for measuring. So just for drill I decided that what the heck let's find out!

I always load with a volume measure and over time I think I have become very consistent at using the measure... I also decided besides testing BH which I use sparingly I would also test T7-2f for volume.

Here are a few pictures that show the process I was using:







And this is the table that was created.... Hope the table makes some sense...



Not sure if this shows anything of much interest but it did keep me busy for awhile...

I would think an almost 10 gr. difference in the BH tube is significant.
I use a CVA brass volume measure, and don't weigh charges. Hope it's close to your TC unit, and these things are made accurately between brands.

bacass said:

I would think an almost 10 gr. difference in the BH tube is significant.
I use a CVA brass volume measure, and don't weigh charges. Hope it's close to your TC unit, and these things are made accurately between brands.

Click to expand...

The tubes actually work out to about 8 grains of BH heavier. Depending on the weight of the projectile that could make a big difference in pressure and velocity. Theoretically an additional 10 grains of any of the real Black powders or any of the subs should not be a problem for most rifles built today. My concern would come when shooting a 400+ grain projectile with a 130 grains of BH.

I have a digital scale but I've found it's not 100% repeatable - I use a RCBS 505 beam scale instead.

Wondering if someone else can verify this:

I was getting ready for the upcoming season one year and I happened to check the previous years quick load of 110gr of BH209 (77gr by weight) and found that it was "lighter". I figured it had dried out in the tube compared to being originally sealed in the container

What's more, every lot of Blackhorn has a different density.

The difference between the carry tubes and the brass measure is interesting but not surprising.

I think the key message here is to be consistent between the ranges and th field. If you always use the same tool, you'll be gtg.

bacass said:

I would think an almost 10 gr. difference in the BH tube is significant.
I use a CVA brass volume measure, and don't weigh charges. Hope it's close to your TC unit, and these things are made accurately between brands.

Click to expand...

Between brands, the measures all measure differently. Powder measures measure differently depending on brand. They measure differently depending on how you use them. If you really really want to know how much powder you are using, weigh your charges with a scale. Grain is a unit of weight. Measuring weight by volume is how it was done on the trail, in 1817. Why do it that way in 2017? :mrgreen:

Good report.

Have you weighed out 84gr of BH209 and put that into the BH209 charge tubes to see what amount it indicates?

I checked their website and it appears that the charge tubes are advertised as load comparison tubes for pre-prepared loads so it looks like one should not use the graduations for measuring loads. Do the instructions that come with the tubes say anything about that?

My best volume measure is a brass swivel top, Traditions or CVA, not sure which but it looks just like my extra CVA measure.

After your post, I checked my TC U-view set at 120 volume, it's a bit more clumsy than my brass measure but seems to work good, weight checked on my RCBS 505
85
84.8
85.4
I use the 'slight mound and tap down' method when I measure volume, I get it to where the swivel top will close without hitting any powder kernels.

Brass measure 120 volume set, slight mound and tap, weight checked on the RCBS 505
83.5
84.2
83.4

BuckDoeHunter said:

Good report.

Have you weighed out 84gr of BH209 and put that into the BH209 charge tubes to see what amount it indicates?

Click to expand...

Good point! let me try that right now!

Here is the weighed powder...



Then into the BH Tube

I checked their website and it appears that the charge tubes are advertised as load comparison tubes for pre-prepared loads so it looks like one should not use the graduations for measuring loads. Do the instructions that come with the tubes say anything about that?

Click to expand...

Yes, pretty much what you indicate. I guess I would not have considered using them for a volume measuring but it did come on one forum or the other.

My best volume measure is a brass swivel top, Traditions or CVA, not sure which but it looks just like my extra CVA measure.

After your post, I checked my TC U-view set at 120 volume, it's a bit more clumsy than my brass measure but seems to work good, weight checked on my RCBS 505
85
84.8
85.4
I use the 'slight mound and tap down' method when I measure volume, I get it to where the swivel top with close without hitting any powder kernels.

Click to expand...

Same here - but the real key is to be consistent each time. With BH there really is not much settling....

Brass measure 120 volume set, slight mound and tap, weight checked on the RCBS 505
83.5
84.2
83.4

Click to expand...

You were certainly closer than I with the Volumes...
Another reason that I really feel for hunting there is not need to weigh individual charges. None of your volume charges would have effected POI much even in perfect atmospheric conditions let alone the external force going on while hunting.

Thanks for the info...

Looks like someone flubbed when they setup the machine for the graduation marks :nono:

BuckDoeHunter said:

Looks like someone flubbed when they setup the machine for the graduation marks :nono:

Click to expand...

I am not really sure... But as has been mentioned the powder varies a bit from lot-to-lot.... the lot I am using was produced in 2009.

I weigh all my charges because I feel I get the most accuracy and consistency by doing so. Powder measures are not always the same. If you fill a powder measurer and tap it with your finger or tap it on the table you'll see that the measurement has now drop from the 110 line so you add more. Your shot is not going to be where the first one was because now you added a little more powder to get back to the 110 grain line. It will be close and if your happy with that then by all means stay with it but if you like real tight groups you may not. I use a very in expensive scale. Never had any trouble with it other then just changing the batteries. It's a Frankford Arsenal DS 750. According to the Blackhorn 209 site, 77 grains weighed is equal to 110 grains in a powder measurer. I weigh all my charges to 78.0 grains and then I pour that charge into a LANES TUBE and there it sits until I uncap it and pour it down the barrel of my MR.
Is there a difference between weighing and using a powder measurer, in my opinion there is. Some may say no but this is the way I do it and will probably never change.

Ray...........( This is my opinion and by no means saying weighing is better then using a powder measurer because I'm not. This is the way I do it ).

hawgslayer

And I would counter that with all the shooting I have done - I really do not see a difference in accuracy weighed versus thrown. - Once you develop a method of throwing powder and stay consistent each time you do it.

Because of the nature of BP and Subs excluding BH. With BP and the Subs - it take 7-10 grains difference to make a noticeable difference in POI. With BH that is reduced to 4-7 grains from load to load.

I have also spent a lot of time shooting over a chrono to check the consistency of the velocities of the shots that have been shot with thrown loads. While there are differences in the velocity they are minor and insignificant at the target.

This target was shot with volume loads - thrown on the tail gate of my pickup.



With all that said - if I were shooting paper for money - I probably would weigh - not sure it would make a difference - but with BH I would feel better about it.

Like I explained, this is what I do and it doesn't mean it's the only way.

Ray............. :yeah:

hawgslayer said:

Like I explained, this is what I do and it doesn't mean it's the only way.

Ray............. :yeah:

Click to expand...

I'm with ya Ray. I measure out 84gr for my 45 cal guns. I measure all my powder. Smokeless & BH.
Greg

Great discussion . Very interesting and informative. Thanks to all. guy

I weigh my BH209 charges (77gr) on an RCBS 10:10 scale.

I believe that the old brass measures were designed in black powder days with the Black that was in use at the time, this will make a difference some of the newer measures were more recently designed hopefully around the most popular sub. Even so mass production will have tolerances and they will not be identical but 10 grains off is to much in my estimation and the BH tubes I had[through away] were just a bit more than that off.

Been looking for some answers:
You won’t find any definition of a blackpowder volumetric grain from the National Institute of Standards and Technology (NIST), or any other source that I know of. The reason is simple; there is none. Blackpowder has always been measured by weight, not by volume; just like breakfast cereal. You buy blackpowder by the pound, and that is weight, not a “volumetric pound.”
Not only does volumetric grain have no exact correlation to weight, it has no precise correlation to performance. Ian McMurchy (in the very same book) chronographed 100 volumetric grains of various blackpowders and substitutes through his Oeher 35P pushing a 300 grain bullet, recording 5 shot average velocities from 1233 fps up to 1594 fps all with “100 grains of powder.”
In my search I also found this:
Oh, I also just read that possibly one volumetric grain of BP is = to a 1 grain of water by volume. So if you filled up a 60 Vgr BP measure with water, the water would weight 60 grains on a scale. I will have to go check this to see if it is correct. If so it would be easy enough to calculate volume of a measure. I have no idea if this is true or not.
To check this
The weight of water equals 62.4 lbs for a cubic foot. This works out to 998.4 ounces.

We can take the weight and divide it by the cubic inches (1728 cubic inches in a cubic foot) to find what a cubic inch weighs.
So 1 cubic inch of water weighs .5777777778 ounces
1 ounce = 437.5 grains. Thus 1 cubic inch of water weighs 252.7777778 grains (.5777777778 ounces * 437.5)
volume = Pi * radius2 * length
So lets put this into action.
If we have a cylinder that is .39" in diameter and 2" long first we find the volume.
V=3.14*.195(sq)*2 = .238797 cubic inches
So .238797 cubic inches * weight of one cubic inch in grains(252.7777778) = 60.36grains of water by weight.
I checked this with a powder measure and it works out to be within a grain or two of the math.
There you have it. A black powder volumetric measure is based on the weight of water.
So one volumetric grain is = to one grain of water.
Greebe

Nothing to do this evening, eh?