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Powder measures and weighing

Posted: Wed Feb 20, 2019 9:48 pm
by rgchristensen
I have done considerable testing of the operation of powder measures. First thing discovered was that ordinary powder scales are pretty much useless in monitoring the performance of a powder measure. A good laboratory scale is required. I have weighed 30+ dumps of about 60 grains of powder and measured a standard deviation of 0.15 gr. In most of the calibers that we use in BP target games, 1 gr of powder is good for about 6 feet/second, so 0.15 gr is "down in the grass", and not to be concerned about. In order to achieve this, it is necessary to operate the measure carefully. When you turn the drum to "fill", take care not to bump the end of the travel. I've installed a little piece of rubber in the measure to make this a gentle stop. If you "bang" the lever up, and "bang" it down, you are going to have problems with weight variation. It is also advisable to use powder that is well-sifted in manufacture, so that there is a minimal distribution of grain sizes. Surprisingly, I have always found very little tendency for charge weights to vary depending on the amount of powder in the reservoir, and have not found a baffle to be particularly useful or necessary. I believe that the reason folks (including me) have had good results with the cumbersome B&M measures, is that the machine FORCES one to operate it properly.

CHRIS
RGChristensen

Re: Powder measures and weighing

Posted: Tue Feb 26, 2019 8:52 am
by rfd
the *ONLY* current commercially available powder measure that actually works amazingly well for me is a harrell's schuetzen. they're worth the big bucks, and i use mine for smokeless handgun loads loads only. this is for 3 grain to 12 grain charges that will average drops at a tenth grain.

all my center fire rifles are black powder only, and powder charges get weighed on a gem pro 250 digital scale. analog scales are too slow and not as accurate as a good digital scale. at least for me. ymmv.

Re: Powder measures and weighing

Posted: Tue Feb 26, 2019 10:08 am
by kenny s
I had been using a BP measure and drop tube...but I started weighing them with my digital scale and they were off
a grain or three.....

so, I use the measure, but then weigh all charges...Ken

Re: Powder measures and weighing

Posted: Sun May 12, 2019 8:27 pm
by John Boy
Deleted

Re: Powder measures and weighing

Posted: Sun May 12, 2019 8:29 pm
by John Boy
the *ONLY* current commercially available powder measure that actually works amazingly well for me is a harrell's schuetzen.
Give this digital a try, you'll like it ...https://www.dx.com/p/kl-50-50g-0-001g-1 ... NjWNEh7l2E

Re: Powder measures and weighing

Posted: Mon May 13, 2019 3:54 am
by rfd
John Boy wrote: Sun May 12, 2019 8:29 pm
the *ONLY* current commercially available powder measure that actually works amazingly well for me is a harrell's schuetzen.
Give this digital a try, you'll like it ...https://www.dx.com/p/kl-50-50g-0-001g-1 ... NjWNEh7l2E
while it might have the sensitivity to .02 grains, the 60 second shut off and battery-only are negatives. still, for $35 it ain't bad on a scale budget. i'll still stick with my gempro 250.

Re: Powder measures and weighing

Posted: Mon May 13, 2019 8:40 am
by flatsguide
Chris,
Thank you for posting your findings. I’m particularly interested in your thoughts and methods of sifting powder for uniformity. I would like to know what size screen you are using to remove the “fines” and did you find any statistical improvement in group size ? One finds very little on this subject and I’m at a point accuracy wise with my .45-70 that little things E.g. primers, over primer wads etc. should start to make a difference. One would think that varying amounts of “fines” in the powder column would have a greater affect on accuracy than different primers, all other things being equal (which they usually are not;-).
I admit I have not done a search but do you or anyone reading this know what screen size is used for different grades of powder ? Are these screens standard with all black powder manufactures ? I’m currently using Swiss 1.5
Thanks Richard

Re: Powder measures and weighing

Posted: Mon May 13, 2019 9:02 am
by Dennis Armistead
flatsguide wrote: Mon May 13, 2019 8:40 am Chris,
Thank you for posting your findings. I’m particularly interested in your thoughts and methods of sifting powder for uniformity. I would like to know what size screen you are using to remove the “fines” and did you find any statistical improvement in group size ? One finds very little on this subject and I’m at a point accuracy wise with my .45-70 that little things E.g. primers, over primer wads etc. should start to make a difference. One would think that varying amounts of “fines” in the powder column would have a greater affect on accuracy than different primers, all other things being equal (which they usually are not;-).
I admit I have not done a search but do you or anyone reading this know what screen size is used for different grades of powder ? Are these screens standard with all black powder manufactures ? I’m currently using Swiss 1.5
Thanks Richard
As a black powder maker I start with a 4 mesh screen and finish with a 12 mesh screen. All kernels that fall through the 12 mesh is then milled all over again. But remember that if you compress your loads, you're defeating the purpose of uniform kernels because they are being broken up in the compression process. Hope this helps.
Dennis

Re: Powder measures and weighing

Posted: Mon May 13, 2019 11:32 am
by SchuetzenDave
For smokeless the Harrell's Schuetzen is extremely precise and there is no need to weight your powder after dropping.

For Black Powder the MVA powder measure gives powder loads with the least variation however I then weigh them with a RCBS 10-10 scale and then precisely top them to the precise weight.

Re: Powder measures and weighing

Posted: Mon May 13, 2019 5:55 pm
by powderburnt
Dennis, will .050" compression crush the BP kernels enough to destroy the original sizing?

HG

Re: Powder measures and weighing

Posted: Mon May 13, 2019 5:55 pm
by powderburnt
Dennis, will .050" compression crush the BP kernels enough to destroy the original sizing?

HG

Re: Powder measures and weighing

Posted: Mon May 13, 2019 7:41 pm
by Kurt
A digital scale is only as good as the tech at the bench takes the time to tune it right with a screw driver before putting it the box.

Re: Powder measures and weighing

Posted: Mon May 13, 2019 8:13 pm
by rfd
Kurt wrote: Mon May 13, 2019 7:41 pm A digital scale is only as good as the tech at the bench takes the time to tune it right with a screw driver before putting it the box.
more importantly, all things being relative, a digital scale is only as good as its calibration consistency.

times have changed and i find good digital scales to be a godsend of both speed and hundereths of a grain better over analog scales.

Re: Powder measures and weighing

Posted: Tue May 14, 2019 3:38 am
by Dennis Armistead
powderburnt wrote: Mon May 13, 2019 5:55 pm Dennis, will .050" compression crush the BP kernels enough to destroy the original sizing?

HG
If you hear the crunching noise of the powder when compressing it, you're changing the kernel size. Some compression will happen in all loads, even if only a little. I...like most reloaders, experiment with different loading techniques, including powder compression. A technique that I have been using for years is powder compaction, not compression. I have a vibrating loading block that settles the powder kernels. Some shooters use a vibrating drop tube instead. If I drop tube a load of 1F into the case and it is, say....063" (1/16") from the top and then vibrate it on the loading block and watch the powder column drop .375" then I just did the same thing as compressing it .375" but I won't have broken kernels. Many pics of compressed loads have been shown on this forum (I think from Kurt) showing different levels of compression. A typical heavy compressed load will show unbroken kernels down by the primer, but up by the bullet the powder is compressed into an almost solid mass that comes out in chunks. Maybe a load like that will shoot good and that is what you're looking for, but I can't see compressing, for example 1 1/2 F into 3 F part of the way down the powder column. Might as well just load 3F with little to no compression and be done with it.
Dennis

Re: Powder measures and weighing

Posted: Tue May 14, 2019 10:31 am
by Lumpy Grits
Have no complaints about my MVA, PM.
Never fill it more than 3/4 full, and never let it get below 1/4 full...... :wink:
Gary