Weighing Powder Charges

[hankfannin]

Thought I'd get some of you to help with this. I've read several tips, articles and posts about folks weighing their powder charges to get the absolute most consistent load possible therefore eliminating one variable that could effect accuracy. I'm wondering how much this could really effect accuracy verses just using a standard powder measure. How many grains off one way or the other does it take to change POI?

I did a test this morning to compare what I think are the two most common methods using a powder measure. 1)pouring the powder into the measure just a little over the top, no tapping or settling of the powder, cutting it off level with the top and then down the barrel. 2) pouring the powder to the top of the measure, tapping and settling the powder and then topping off and cutting level. ( the tapping and settling part is a ritual for many folks).

Anyway - I used a Hornady GS-1500 electronic scale and tried both methods, one with ten taps on the side of the measure and one without any tapping or settling. I did each test 5 times and tried my absolute best to be consistent. The straight pour and cut off level method resulted in a 0.7 grain difference in powder weight. The tapping and settling method gave me a 1.2 grain spread.

I really don't know if 1.2 grains of powder would make a difference in POI. Maybe, maybe not, everything else being equal. My test proved, to me anyway, that tapping and settling is not the most consistent method. Actually when you think about it, when you are tapping, shaking, whatever, to try to settle the powder in that measure you are introducing a bunch of variables that IMHO no one could duplicate time and time again. Of course this is all just my opinion and nothing else.

Greyhawk

 

[mooman76]

The key is constancy. Measure the same way all the time tap or don't tap doesn't matter that much as long as it's done the same. If you are going to tap 3 times to settle, do it every time. It's the same with smokeless powder when loading modern cartridges. They usually don't weigh every powder load either. Weigh to know what they are and every so often to make sure it is staying the same. But to get the powder thrower to throw consistent, must do it the same. Tap or don't tap. What works better for one, may not be better for another.

 

[wayne terry]

Greyhawk45
Man been there done that also.
Since BP is mostly measured by volume instead of weight it in my opinon also and since BP burns very fast does not make that much difference,over the years I have tried to melt the bbls. out of my rifles doing this with BP and every BP substatute I could get my hands on very little difference if any was ever noticed, but then again as I said before I'm not the best shot in the world.

 

[Larry Pletcher]

As with most ideas there are exceptions involving weighing charges. I agree with the earlier poster in general. When shooting patched round balls at normal hunting and target distances, weighing probably isn't necessary.

There are a couple of types of shooting where it does aid in accuracy. The bullet shooters shooting 500 yardages weigh charges both at Friendship Slug matches and 1000 yard matches at places like Oak Ridge. Because of the drop of heavy bullets at these extreme ranges, variations in charges may cause vertical stringing. Perhaps a couple of our members who shoot long range bullet guns will help here.

For me and for 99+% of us shooting patched round balls, I seriously doubt we can tell the difference. I'm a far bigger variable that ball weight or powder weight.

Regards,
Pletch

 

[Col. Batguano]

Most cartridge reloaders use a volume-based charge thrower too. They set their volume based upon weight of the charges thrown. Since many smokeless powders vary greatly in density regarding powder type (ball, extruded, flake etc), a 1 size fits all scale can't be used on the charge adjustment mechanism. Generally, the denser the powder, and greater the charge, the less percentage variation you get from throw to throw.

It would be interesting to see what your results would show as a variation going up and down the BP grading scale, from 4F to Cannon. :hmm: I bet in a small charge, like maybe 15 grains, your percentage variation (by weight) will be greater than in a big charge, like 120 grains.

 

[Claude Mathis]

For me and for 99+% of us shooting patched round balls, I seriously doubt we can tell the difference. I'm a far bigger variable that ball weight or powder weight.

My point. :thumbsup:

 

[Melnic]

I do cartridge reloading. For rifle precision, EVERY one is weighed to within .1grain.

Pistols, I'll use a powder thrower and typical variance within say 50 rounds is still .2 grains.

With Say Centerfire Rifle reloading if your doing what's called Optimum Charge Weight load testing (OCW), small variations in powder weight won't make a difference in POI at shorter target distances.

I've read where many BP shooters work up a load and choose a load where 3 adjacent loads all have the same POI (that's what OCW mostly is). Thus variations in charge weight will not affect accuracy.

Well, that being said, I weigh my charges. I first take 3 volumetric measurements, then look at the ratio of volume to weight. Goex FFG is pretty much 1:1. BP subs are going to be different. I weigh it cause I don't have a calibrated scoop and I can do it fast. But my main reason for pre-measured weights is to have little plastic vials of pre-measured powder ready to go and save time at the range. I've seen others with pre-measured vials that were measured volumetrically. They pre-measure just for convenience at the range.

Just like with centerfire cartriges, powder weight is just one piece of the equation. I have a Mosin Sniper and when I slugged the barrel and went to a larger diameter bullet, the difference in groups shrunk to half.

SO, if a small variation i powder moves your 50 yard groups, I might say you may want to change your charge.

 

[Rifleman1776]

What Pletch said.
Right on. :thumbsup:

 

[hanshi]

:thumbsup: +2. Black was meant to be measured by volume and with consistent pouring a volume measure will give accurate measurement. I make the measure first then weigh the results. If it is not quite what I want I'll deepen it until it is.

 

[roundball]

For me and for 99+% of us shooting patched round balls, I seriously doubt we can tell the difference. I'm a far bigger variable that ball weight or powder weight.

My point. :thumbsup:

To say nothing of the fact that weighing by itself doesn't eliminate whatever burn rate / velocity variables that might be introduced from different amounts of "fines" in one powder charge compared to another.

 

[bpd303]

I found the same thing. All powder measures are not equal. I have three adjustable measures and they all throw a different weight at the 70gr mark. The one I use the most is accurate at all settings. The ones that are off are marked along with my fixed measures.

 

[Grenadier1758]

I have measured about 6 powder measures. The actual weight compared to the volume setting can be off by several grains. I believe that the maximum difference was about 4 or 5 grains at the 100 grain setting. 3fg powder was closest in weight to the volume setting. 2fg was slighter lighter in weight at the 100 grain setting.

When shooting for accuracy select one measure and only use it and fill it the same way. Tapping three times to settle the load before leveling reduced the deviation in weight and raised the weight by about a grain or two.

 

[galamb]

I agree with Sam Fadala (Lyman Manual) on this one.

His point is - your rifle doesn't know whether you put 70 grains or 72.4 grains down the barrel and given the inherent inefficiency of black powder it doesn't care.

A 5 grain spread may produce a noticeable difference, but a grain of two one way or the other is probably way beyond what the average shooter would see/notice etc.

Depending on what YOU call accurate, a grain or two difference in the balls, a mil or two difference in ball diameter and slight differences in patch thickness may also have "zero effect" on how YOU shoot.

I use the fixed powder measures - just fill/dump (not particular about tapping/scraping) - off the shelf round balls - Hornady or Speer (whichever is available) - and pre-lubed Ox-Yoke patches.

Everything I use flies against those that use scales, micrometers and calipers to assist with "their loads".

But for me, that "off the shelf combo" CONSISTENTLY produces sub-2" groups at 50 yards which is all "I" need for what I use my rifles for.

All that "horsing around FOR ME" would be a waste of time.

So it depends on what YOU require for accuracy....

 

[Don Steele]

Screening one's powder eliminates those issues. :thumbsup:
Doesn't everybody screen their powder...???
:hmm:

 

[Darkgael]

Screening one's powder eliminates those issues.
Doesn't everybody screen their powder...???

Life is too short to screen powder.
Pete

 

[Grenadier1758]

Screening one's powder eliminates those issues.
Doesn't everybody screen their powder...???

Life is too short to screen powder.
Pete

Its much easier to sock ones powder to pick up the fines. Take one worn out heavy cotton sock and a half can of powder in a large coffee can. Roll it around for a few minutes so the fines get caught up in the sock and you're good to go. You can always wash the sock to removes the fines and be ready for the next batch.

 

[roundball]

LOL...as I often say, nobody would ever confuse me with a purist...but I do try to at least follow the most simple basics that I understand the settlers did...and I'm pretty sure "Daniel" didn't "weigh his charges" or "sock his powder"
:wink:

 

[Grenadier1758]

I'm sure Daniel didn't weigh his powder either. Most likely he poured what he considered a reasonable amount in his palm and dropped it down the barrel. If he was being real precise, he would put a ball in his hand and pour powder to cover, hold the ball with his thumb and pour the powder down the barrel.

 

[Billnpatti]

I wondered about the same thing but could find no published emperical data. So, I ran my own experiment. First, I wanted to see how accurate my measurements were if I did not settle the powder in my measure. The test was conducted using 10 measurements at each of 7 dfferent powder measure settings ranging from 55 grains to 85 grains in 5 grain increments. The powder was Goex 3fG. The powder measure was a Treso adjustable measure with a swing over spout. The charges were weighed on a Lyman LE-300 electronic scale. Ten meassurements were done for each of the 7 settings. The powder measure was carefully filled with no tapping to just over full with a small mound on top. The spout was swung over to cut off the excess powder and the powder was poured into the pan of the electonic scale. The charge to charge variation over all 70 measurements was found to be plus or minus 0.3%. with a standard deviation of 0.2%. The average deviation from the measure setting was found to be -2.9% with a std. dev. of 1.0%

I then selected a setting of 80 grains on my powder measure and made 10 measurements in which I filled the powder measure and tapped on the side until the powder stopped settling and a small mound of powder was left on top of the measure. Again, the spout was swung over to cut off the excess powder and the charge was weighed. The average weight over the 10 weighings was 80.42 grains with a std. dev. of 0.2 grains The charge to charge variation was 0.3%. The deviation from the measure setting was 0.5%.

The charge to charge variation is the same for both the un-settled and for the settled powder measurements. This means that so long as you are careful to be consistant in how you measure your powder, your charge to charge variation will be minimal whether you choose to settle your powder in your measure or not settle it. However, I found that if you do not settle your powder, your charge will, on average, be approximately 3% less than the setting on your powder measure. Whereas, if you choose to settle the powder in your measure, your powder will, on average, be only 0.5% greater than the setting on your measure.

In summary, it does not make a significant difference whether or not you choose to settle the powder in your measure on not settle it. The main thing is, as we have always known, consistancy. So long as one chooses one way or the other to measure their powder and do it consistantly, our powder charge will have a very small charge to charge variation. For the avereage off hand shooter, this small variation will be insignificant.

For those who poo poo the idea of making such measurements to determine the accuracy with which one can make their powder measurements, let me say this: The final word on muzzleloading was not written in 1830 nor 1870 nor in 1910. In fact, the final word in muzzleloading has yet to be written. So long as there are people who want to better understand what is going on interior or exterior to their muzzleloading rifles when they fire them and are willing to conduct experiments and share their data, we who read this data will continue to build on the knowledge that Davy or Dan'l had. There is information on the subject out there, yet to be had. Let us never cease in our search for it.

 

[Artificer]

Well, I guess I'm one of the few folks who actually has seen an accuracy difference with a VERY small difference in powder volume in one rifle. It is in a contemporary flint rifle in .45 caliber that was built in the early 70's with a Siler Lock and Douglas straight sided barrel.

The type accuracy I demanded was the completely consistent ability to cut a string (with a weight on the end holding the string taught by gravity) with a single rifle ball at 25 yards and keep all shots in at least the 10 ring of the targets we used at 50 yards. Now of course I was not able to do that consistently except off a bench rest, but I demanded it from my rifle to compete against some pretty darn good shooters at Friendship and some large local club matches. That rifle gave me fits getting the best accuracy load until I started changing the powder volume by 1 grain at a time and finally split that down and found that 42 1/2 grains by volume was the load that would do it. I then cut a non adjustable powder measure to that exact charge by finely filing the top till it gave exactly that charge when I overfilled it a bit and used a knife to cut it off exactly on top of the measure.

However, only a few years later I owned an original .36 cal. half stock percussion rifle that was circa 1850. Not a target rifle, just a regular hunting rifle. That rifle was THE most forgiving BP rifle I have ever owned. It shot two sizes of balls with the same powder charge and that one was good within almost 5 grains difference.

Gus