Update on vibration to settle powder plus some density differences

[TexasMac]

A couple of months ago I posted an article on my website titled, Using Vibration to Settle & Compact Black Powder (http://www.texas-mac.com/Using-Vibratio ... owder.html). The article was also published in the August 2020 edition of the Single Shot Exchange Magazine. The article was based powder from 3 cases of 2012 vintage Swiss 1.5Fg powder which I finally “burned through” and turned out to be significantly denser than the more recent lots of Swiss 1.5Fg. Hence there was little difference in using a drop tube vs. vibration. Not so with some 2016 (lot # 18-01-2016) powder I just started using. Using the newer “fluffier” powder resulted in a significant difference between settling the powder with a drop tube vs. vibration. I just finished comparing the two techniques when loading 55.5grs in a .40-65 case. Loading the same 10 cases using each technique resulted in an average difference of 0.040”. I.e., the level of the powder in the drop-tube cases was 0.040” lower than in the cases with the powder settled using vibration, which resulted in a compression reduction of 0.040” or equivalent to about 1.5grs of 1.5Fg powder in a .40 caliber case.

By the way, all being equal (same wad, same bullet, same COAL, etc.), with the exception of the old vs. the new powder, 55.5grs with the old 2012 powder resulted in an average compression of 0.085” while 0.165” of compression is required with the newer 2016 powder. Since I have a case of the 2016 powder I’m considering mixing 3Fg with it to reduce the compression amount and also using a drop tube rather than vibration to help in reducing the required compression. I have found that Swiss works better for me if the compression is limited to 0.100” or less.

For some more density comparisons, I also have several pounds of 2017 Swiss 1.5Fg (lot # 27-11-2017) and ran a compression comparison with 55.5grs using the drop tube. It’s even fluffier than the 2016 stuff and required 0.185” of compression. And just for “kicks”, using a drop tube with 55.5grs of Swiss 3Fg (lot # 30-04-2018) resulted in 0.152” of compression which surprised me. I expected the compression to be significantly less. Finally, I checked some 3Fg (lot # 15-04-2019) resulting in 0.079” of compression. Obviously the 2019 3Fg is a good bit denser than the 2018 3Fg.

Should those of you reading this wish to make a similar comparison between different lots, be sure to use the same case to eliminate differences in volume capacity. I did use 10 separate cases that were sorted and selected by weight to make the earlier comparison of using a drop tube vs. vibration, but the weight spread was no more than 0.2grs. Regardless, for a more precise test, the same case was used several times with each powder to check the noted relative compression of several lots and powder granulations.

Wayne

[TexasMac]

The following condense all the info in the previous post.
All things equal the average compression required:
1.5Fg old 2012 powder: 0.085”
1.5Fg (18-01-2016): 0.165”
1.5Fg (27-11-2017): 0.185”
3Fg (30-04-18): 0.152”
3Fg (15-04-19): 0.079”

Wayne

[art ruggiero]

thanks wayne for your tireless testing art

[Glen Ring]

Thanks for posting this...and all along Ithought swiss 1.5 was just swiss 1.5..lot after lot after year.

[martinibelgian]

Nope, my last lots even changed the volume/weight difference between Fg and 1 1/2Fg. Radicallyactually. 76,7 grains of Fg has the same volume as 82,1 grs of 1 1/2Fg. That used to be the other way around normally...

[Kenny Wasserburger]

Wayne,

I used to compress right at .285 with Swiss 1.5 in my 38-50. Shoot numerous perfect scores of 100-ax’s in the 3-6 range with that amount compression. Did pretty will with it in Target Rifle Mid-range Prone in 2015.
I gave up on it after that the 38 1-14 twist gave up to many points at 600. We voted on the 3-5-6 format to use from then. I went on to a 1-14 40-70 SS, and compress that powder in it quite a bit.
I don’t have my notes handy but it’s .200 plus.

Kenny Wasserburger

[TexasMac]

Kenny,

Although I prefer to stay under 0.100" of compression I doubt I'll be able to reach that level with the new powders, even mixing 3F with the 1.5F. I actually did pretty good at a recent match with the 2016 1.5F powder which required right at 0.205" of compression, but I was using vibration to settle the powder for that match. As noted in my opening post, using a drop tube lowers the required compression down to around 0.165"

BTW, since I've accumulated several different lots of powder by buying and also winning some at state and regional matches, it's been my practice, to thoroughly mix it all together & figure out the best load with the results. Based on what I have now and my average powder consumption, I should have around 4 years worth and it will be all the same custom blend.

Wayne

[semtav]

Just did a quick check of two 1.5 FG powders. One from 2010 and one from 2017
full 45-90 case dipped, the 2017 weighed 91.6 gr, the 2010 weighed 98.2 gr

drop tube vs vibrate on the 2017 powder with the same 91.6 gr powder
.165 down vs .110 down.

Have had great results with lots of compression from the older powders *

* Local match results only !!

just started testing a 45-90 load with the new powder so no opinion on compression with it yet.