Comparing some 2F and 3F hunting load velocities

[Sinner]

Exactly my point in my :stir: . We refer to a charge as grains, knowing it's technically a weight measurement while we are using volume.
It may be interesting to see if there's any difference in weighed vs. measured charges, but I doubt it.

 

[gizamo]

My head hurts...

 

[roundball]

It may be interesting to see if there's any difference in weighed vs. measured charges, but I doubt it.

There almost always is some difference...and it varies based on the brand of powder and granulation size.
Used to be that Goex 2F was a reliable 1:1 standard...but so many other brands have become available with different compositions and weights that it's no longer as straight forward.

As Zonie and others mentioned...and based on that original 1:1 standard...the use of the volumetric powder measure setting expressed in 'grains' has long been a common means of communicating powder charges within the ML community.
As a general rule, I don't think traditional ML enthusiasts routinely weigh and communicate their charges in terms of scaled weight...at least I never have.

 

[Herb]

I used to think Goex 3F was heavier than an equal volume of Goex 2F, but my powder is not. I have a 25 pound bulk bag of Goex 2F and another of Goex 3F from Fort Bridger Rendezvous in 2008 and 2009. In comparing Swiss powder to Goex, I finally weighed equal volumetric charges and then weighed the adjustable powder measure charges to see how consistent they were. I finally had to make a weight-calibrated measure for each powder and granulation and each charge I wanted to compare, 40, 55, 70, 80, 90 and 100 grains. I used a .300 Weatherby Magnum fired cartridge case with an extension soldered on the neck to file to an exact 100 grains of Goex 2F. I measured 12 times and the average was 100.6 grains weight. The same measure held only 97.08 grains of Goex 3F but 113.35 grains of Swiss 3F. I was then out of Swiss 2F, but it and Swiss 1 1/2F weigh more than an equal volume of Swiss 3F.

 

[roundball]

I used to think Goex 3F was heavier than an equal volume of Goex 2F, but my powder is not.

I always assumed that too, based on the assumption that like finer birdshot, it would pack more densely, be less air space, etc.
But in actually checking, I found that's not the case with my Goex, my measures, and my methods.

In testing, I poured powder into the measure from the Goex can having a brass spout on it...I didn't settle it, tap it, jar it, etc...I just leveled it and then weighed it.
Using the 100grns setting of a T/C adjustable brass powder measure, the charge weights were:
Goex 2F average weight = 100.x grns
Goex 3F average weight = 94.x grns

I believe that with the smaller 3F granulations of Goex and the greater number of jagged edges, they catch against each other more than 2F and instead of packing tighter, fill up the measure higher / sooner...ending up weighing less as a result.

 

[Sinner]

It may be interesting to see if there's any difference in weighed vs. measured charges, but I doubt it.

There almost always is some difference...and it varies based on the brand of powder and granulation size.
Used to be that Goex 2F was a reliable 1:1 standard...but so many other brands have become available with different compositions and weights that it's no longer as straight forward.

As Zonie and others mentioned...and based on that original 1:1 standard...the use of the volumetric powder measure setting expressed in 'grains' has long been a common means of communicating powder charges within the ML community.
As a general rule, I don't think traditional ML enthusiasts routinely weigh and communicate their charges in terms of scaled weight...at least I never have.

I should have clarified.... I doubt the difference in weighed vs measured charges have any real affect on velocity or accuracy.

 

[Zonie]

There was a link recently that led to a table of weights published by Lee for their dippers.

It was a Adobe PDF file so after downloading it I stored it in my Black Powder Folder on my computer.

I have no idea what the brand of black powder they used to determine this but looking at their table shows that one cc (cubic centimeter) of 3Fg weighs 15.930 grains.
One cc of 2Fg powder weighs 14.697 grains.

This seems to bear out the common sense idea that the finer powder granulation has smaller air spaces between the grains although admittedly there are more of them.

Interestingly (at lest to me) is that the actual weight of the 3Fg powder per cc is 8.4 percent larger than the actual weight of 2Fg powder per cc.

I wonder if this has something to do with the old adage about reducing the powder load 10 percent when switching from 2Fg powder to 3Fg powder?

 

[roundball]

I should have clarified.... I doubt the difference in weighed vs measured charges have any real affect on velocity or accuracy.

Totally agree...

 

[Mike Brooks]

Gosh, who would have ever guessed 3fff would have more velocity than 2ff? :youcrazy:

 

[Herb]

So Lee says Goex 3F weighs 8.4 percent more than an equal volume of Goex 2F. That is not what Roundball and I found. So my 100 grains 2F weight-calibrated measure should have held 108.4 grains of Goex 3F, but it actually held only 97.08 grains, average of 10 measures. I tested weight-calibrated measured charges in my .40 Wigle flintlock I built, everything constant except the charge and powder. Here are the results. The targets are paired top to bottom, except for the right two. These are all MEASURED charges, but with measures that are cut to hold that exact weight. No one series probably varied more than .4 of a grain from the nominal charge. Each ball was seated with a damp cleaning patch on the jag, and the bore was cleaned after the 3F series. This rifle usually throws the first shot from a clean bore faster than the following shots, thus I deleted it on the top left and lower left targets. This rifle has a 15/16 x 44" Rice barrel. All shots were well held from bench and there was no significant wind and no shots were called out. Why some combinations grouped so well and others badly I do not know.

On the left pair, 40 grains of Goex 3F (top) gave 281 fps more velocity than the Goex 2F below it. Second pair, 55 grains of Goex 3F was 224 fps faster than the Goex 2F below it. Third pair- 70 grains of Goex 3F was 175 fps faster than the Goex 2F below it. On the right- 80 grains of Goex 3F at top and 90 grains of Goex 2F at bottom. If someone wants to demonstrate how to cut that velocity dispersion down to very low numbers, lets see your targets.

 

[roundball]

I think it must be two different approaches Herb...the common sense suggested may be an assumption that once a measure is filled, everybody taps/jiggles the measure to completely settle the 3F granulations, eliminating much air space so the measure could physically hold more 3F the weight could get up there.

But as I said for my particular test method, I simply poured 3F into a T/C adjustable brass measure at the 100grn measure, from a Goex can with a spout until the measure was full, leveled and weighed it...averaged 94.x grns on digital scales.
(Goex 2F averaged 100.x grns)

IMO, without tapping/jiggling, the kernels that are simply poured in are all resting on each others edges, filling up the volume sooner...if I get some time in the few days to set back up, I'll remeasure both ways (with and without tapping / settling) and see what's I get.

 

[Deadeye]

I have to agree with Herb and Roundball. I've weighted Goex 2F and 3F many times over the years.
on several different scales and with several different measures and 2F has always been heavier.I will admit that I thought it would be the other way but it isn't.
Deadeye

 

[Herb]

Thanks, Deadeye. I make pour spouts for powder cans from centerfire rifle cases soldered to the lid, with the base drilled out. When I pour a measure full, I very carefully hold the spout to the measure (also a cartridge case) and pour it full. No shaking or bumping, just level the top of the powder. This gives very uniform results.

 

[George]

My results are just the opposite of those reported by Roundball and Herb. I've tried it many times, using a couple of digital scales and a variety of measures, and it's always the same.

In my hands, any volume of 3F always weighs more than the same volume of 2F.

Spence

 

[gmww]

Thanks your posts are often very informative. :thumbsup:

 

[Sinner]

I think all of this is very interesting, especially to note that different people get different results measuring the same things. I think it really depends on the particular methods/steps used.
While it is all very interesting, I'm not sure how important it is in the every day scheme of shooting though. What seems to be most important is that, whatever method is used with which ever powder is used, that the utmost accuracy depends on consistency, whether weighed or measured. But for hunting, is the difference of 2-3 grains by weight or volume going to make any appreciable difference in accuracy or performance?

 

[Sinner]

BTW, roundball, Thanks for the information. It's as I've believed but never tested yet myself (3f providing higher velocities than 2f).

 

[Darkgael]

" I measured 12 times and the average was 100.6 grains weight. The same measure held only 97.08 grains of Goex 3F but 113.35 grains of Swiss 3F. I was then out of Swiss 2F, but it and Swiss 1 1/2F weigh more than an equal volume of Swiss 3F."
That was my experience also.
Perhaps that is why Swiss has a reputation of being "hotter" than other powders.....there is more of it in the same volume.
97 grains of FFFg Goex vs. 113 grs. of Swiss FFFg from the same volume.....a 16 grain difference.

 

[hanshi]

I think you are correct with your conclusion. :thumbsup:

 

[roundball]

I measured 12 times and the average was 100.6 grains weight.
The same measure held only 97.08 grains of Goex 3F

Curious to know what method you used ?
IE: did to tap and settle the measure contents and keep filling the measure with Goex 3F...or did you just pour loose until full, then level it and weigh it like I did?