drum powder measure drifting?

Sometimes I think we've taken the fun out of shooting and reloading. We used to take the dies out of the box, set up our scale/balance, measure or "cups", load up, seat the bullet and go shoot. Usually got atound an inch at 100 yd.

Now, you're not a "serious" shooter unless you have all the techie tools; neck turner, pocket swager instead of a pen knife, scales that weigh to the atomic level, or at least to the powder granule, special dies for full length or neck sizing, special bullet seaters that seat to the nearest ten thousanth,.....

Now, I'll admit, I do like to tinker, but at the end of the day, my military wooden warriors won't benefit from all of this "TLC". I know it depends on the discipline in which you shoot. Mine's how good can I do with what I have. I wonder if anyone has done a time and motion study on our reloading...not to see how much each shot costs, but how much time it takes to produce each round? You'rn vs mine LOL

PWC said:

Sometimes I think we've taken the fun out of shooting and reloading. We used to take the dies out of the box, set up our scale/balance, measure or "cups", load up, seat the bullet and go shoot.

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I have to agree, at least to some extent.

I've commented before, that when I started reloading, back in the late 1980s, I didn't even own a scale.

I had a set of Lee dies which came with a scoop and a page of instructions, and a Lee Hand Press. I split a pound of powder with a friend, and we got after it. We had a bucket o' fun.

I loaded for several years before I acquired a scale in a trade. Would my loads have been "better" if I had weighed every charge?

We'll never know. Although, sometimes I miss the simplicity.

PWC said:

Consistency comes from technique and powder column "setteling". I do not have my measure attached to my bench, but isolated on a smaller bench. Any bump or bang to the bench from press operation causes setteling in the column. My charges got morr consistent aftet doing this.

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I agree.

For single stage loading, I have a separate floor stand for the powder measure to minimize any vibrations from the loading operation getting into the powder measure.

Walkalong said:

Yep, I try to be consistent in my speed on the handle up and down, and try to "bump" the handle at the down stroke on my LNL the same each time. I do not size while loading so that really makes it much easier to do this.

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I have found I get greater variations from the powder measures used on my progressive presses. I have a harder time being consistent operating the progressives than the single stage. There are lots of vibrations and shaking of the powder measures on a progressive.

I do find the Dillon slide bar powder powder measure to be less sensitive to the vibrations and shaking.

Not resizing at the same time as loading does help reduce the powder charge drifting.

I personally have not seen a difference and this is while using an Auto Index Turret press, a Pro1000 progressive press and a Auto Breech Lock Pro press. On these presses I have used 2 different Lee Auto Disk measures and an Auto Drum measure. In these I have used Accurate AA powders, Hodgdon HP-38 and Ramshot Silhouette. Loading 380auto, 9mm and 45acp.

The HP-38 has historically had the greatest deviation from drop to drop and even that in the 3gr to 6gr has pretty much been able to hold within 0.1gr of my set point. The worst case is once in a while I get one that is .2gr over and that always seems to happen after a shell has not lined up straight under the die for the measure and I get a bind and a jump. Then the charge is almost always .2gr over the set point. While with the Western powders these measure are mostly spot on the set point or at least close enough that I cannot read a change on my balance beam scale. Then when I do see a change it has consistently been about 0.05gr light.

I can live with these parameters all day every day.

Also I just finished loading up over 300 380 sample loads with new cast bullets with HP-38 and AA#2 and every single charge was weigh checked with the same results listed above and these were all loaded on an old Lee 3 hole auto advance turret press. Now I also do not see me doing anything different or special to get these results.

If it is two different lots of powder I would say the change is most likely due to the lot of powder.
Different VMD for each lot.
Some powders are more consistent lots to lot about how much x (say .5cc) of powder weighs that others

If both lots are close to the same age you can mix the to even it out (some say this is a bad idea)
I wouldn't want to mix a 3 year old jug of powder with a new one but if I bought one say 3 months age and I get a new one I will mix say 1/2 a lb of the old with the 1lb of new,
(In CA you can't have much powder on hand so no stocking up with 5 or 6 8lb jugs)
For fun when you get a new lot fill the measure to a certain point with the old lot throw some charges close to what you want say 10gr, then change to the new lot with the same measure setting and level of powder and see if it is off by a bit.
In most of the time it will be off a little.


Oppss didn't read OPs last post. (but I will leave the above anyway)

One would think if anything the powder would settle in the hopper the more you load and pack down resulting in heavier charges at the same setting.

Rule3 said:

The method of using an "average" is a falsehood regardless of the powder measure used. It is just that "an average".

You could drop 8 times with 10 grains then one could be a 0 and then one with 20gr. Yes that is exaggerated but several drops could be over a little and some under but as an "average" it comes out looking good.

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While I salute your overall knowledge, your first and last statements simply don't "play well together".

• Admittedly, finding the Standard Deviation and Extreme Spread would be a better method, but it is beyond the mathematical capability of many here. That is why I suggested averaging.

You are quick to scuttle other's suggestions, while not offering any replacements. So my question you is: Exactly what method would you have the OP use then, to avoid the "falsehood" ? Using a single, random drop to set the PM is clearly NOT the answer.

rfwobbly said:

While I salute your overall knowledge, your first and last statements simply don't "play well together".

• Admittedly, finding the Standard Deviation and Extreme Spread would be a better method, but it is beyond the mathematical capability of many here. That is why I suggested averaging.

You are quick to scuttle other's suggestions, while not offering any replacements. So my question you is: Exactly what method would you have the OP use then, to avoid the "falsehood" ? Using a single, random drop to set the PM is clearly NOT the answer.

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I did not "scuttle" others suggestions only yours. Averaging just spreads the error out over the number of drops. So I don't agree with you,
Do you have and use the Lee Powder Measure? I have no solution as I am not there to see how the OP has it set up, and not being clairvoyant I can't help him. You fix it for him

What's wrong with taking 10, 20 30 drops and weighing each one?
The OP mentions Longshot but no bullet weight. Were is the 10 gr data? Also something about H110) leaking? I use both and have no issues with leaking?? Maybe that is a clue??

If seeking Zen Perfection in Powder measure perhaps the Lee Measure is not the Droid you seek. It works fine for me. Better call Lee must be another Lee defect.

Use what ever method you want to, You will always be correct at all times.

OK, I'll wade into this PM discussion with what I have done to all my Lee measures, Auto Disc/Auto Drum.
I've posted before about this but it was mostly ignored/and not really accepted as having any merit.
After seeing Powder Measure Weights sold ebay and reading the reviews I decided to make one to fit the Lee measures I have.

https://www.ebay.com/itm/Dillon-Pow...717746?hash=item215688a9f2:g:~2oAAMXQfvlSn-vX
Here's others:
https://www.ebay.com/sch/i.html?_fr...osacat=0&LH_ItemCondition=4&rt=nc&_dcat=35566

I made a simple/light wooden weight, no guide rod or cap, and have been using it since.
Yes I use the 10 throws/average method with a twist...I do it 10 times
Not sure how that fits into the debate going on here
The only down side of using the weight is powder used in a weight check cannot be put back in the hopper.

I couldn't find a "yawn" smilie so

When mine drifts I dump the powder back where it came from and wipe it out with a dry paper towel and it's good.

I've operated my drum style powder measures enough that I have a good idea of how consistent they are. If I operate the powder measures consistently, they throw consistent charges within an acceptable range of variability.

But, they do drift a bit over a reloading session and I'll admit, I do not have an answer as to why. Sometimes they drift to heavier charges, sometimes they drift to lighter charges. Measuring check charges periodically keeps me up to date on the powder measure is doing. I make adjustments in the powder measure settings as needed but I'm conservative in making adjustments.

Usually, I check the charge weight thrown periodically to insure the weights have not drifted. If the weights have drifted, I'll measure additional individual charges and at times will throw ten charges and look at the average.

I'm comfortable with my operating technique that I do not get the extreme ranges of powder charges and therefore using averages provides acceptable, useful information. When doing check weights, if I get something way out of reasonable range of variability, I'll do the check weight process again.

On progressive presses, for cartridges where I cannot easily visually see the powder level in the case, I'm happy using a powder cop die for checking the powder level in a case before seating the bullet. I'm looking for a powder drop that is in a reasonable range. I'm looking for way too light or way too heavy a charge. I'm finding that while the powder cop system may show a charge that is way off the desired charge weight, it actually weighs within acceptable variability.

I still stop and check the weight of the powder charge periodically.

On a progressive press, even with checking the powder charge thrown periodically, and resizing at a different time as reloading, I still load more ammunition faster than I can shoot.

cfullgraf said:

I've operated my drum style powder measures enough that I have a good idea of how consistent they are. If I operate the powder measures consistently, they throw consistent charges within an acceptable range of variability.

But, they do drift a bit over a reloading session and I'll admit, I do not have an answer as to why. Sometimes they drift to heavier charges, sometimes they drift to lighter charges. .

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I too use some form of Lee Auto measure in my reloading and have become quite comfortable using them and understanding exactly what their limitations are and how consistent they are with each powder I use.

In post 30 I referenced loading some test 380 rounds, I was using a Lee Auto Drum set to throw HP-38 @ 2.8gr and while weighing each drop I loaded 40 rounds that were lubed and 40 of the same bullet that was coated. I then loaded 30 of a different design with the same charge. A few days later I went back to load a few more of a 3rd bullet with the same charge and what happened was I filled the hopper as I normally do and dropped my normal settle charges and then did my weigh check. This time the exact same setting on the measure was consistently dropping 2.7gr. Confused I dumped the hopper and refilled it and rechecked my balance scale again. Again it was a consistent 2.7gr.

Same lot of powder, from the very same container on the very same press with the very same measure. The only thing that changed was the day. So the volume should still be the same as the cavity didn't change only the weight. I went ahead and loaded these as-is and marked the weight at 2.7gr so I'll see what happens. Guessing I will not see a difference.

I still have no clue why the weight change.

The scale is a Gem-20.

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That’s why I asked, you are expecting too much from a <$20 scale. It can give you numbers but I wouldn’t trust them.

I have one and have tested it beside other stuff I have. For example if I hole punch out of cardboard and place it on the Gem-20 I get.



I put the same thing on an old 505 set on one tenth and it shows to be a bit heavier.



Same thing with an old 10-10.



So I drag out an A&D balance and it tells me I should trust the old beam scales more than the gem 20.



I agree with others that even a tenth of difference won’t hurt you most times. You could likely not even be able to tell a half a grain difference +/-.25, in your handgun loads accuracy wise. In any case try weighing the exact same charge or thing over and over to see if the instrument changes reading. Might be surprised what you learn.



I think one issue of the gem 20 is that it “times out” and shuts itself off where any precision digital balance manual will tell you to turn it on and let it sit for 30 min to stabilize, the gem 20 just can’t do that.

I think jmorris is onto the real answer here. A lot of what gets chalked up as "drift" or even "bad metering" is really just randomness in measurement caused by exceeding the resolution of the instrument.

If the scale is good to +/-0.1 grains, which would actually be pretty good for a cheap measure, then it can easily seem as though your powder measure is "drifting" by a couple of tenths.

Signal-to-noise ratio is a very useful concept for understanding all kinds of things in the world. When you start interpreting noise as the signal, you can really go on some wild goose chases.

Tilos said:

OK, I'll wade into this PM discussion with what I have done to all my Lee measures, Auto Disc/Auto Drum.
I've posted before about this but it was mostly ignored/and not really accepted as having any merit.
After seeing Powder Measure Weights sold ebay and reading the reviews I decided to make one to fit the Lee measures I have.

https://www.ebay.com/itm/Dillon-Pow...717746?hash=item215688a9f2:g:~2oAAMXQfvlSn-vX
Here's others:
https://www.ebay.com/sch/i.html?_fr...osacat=0&LH_ItemCondition=4&rt=nc&_dcat=35566

I made a simple/light wooden weight, no guide rod or cap, and have been using it since.
Yes I use the 10 throws/average method with a twist...I do it 10 times
Not sure how that fits into the debate going on here
The only down side of using the weight is powder used in a weight check cannot be put back in the hopper.
View attachment 856363
I couldn't find a "yawn" smilie so

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OK, if that works for you but I still question what it really does in a LEE hopper??

Take the hopper off and look at the very small hole in the bottom (plus there is a little ledge) Do you really think that weight on top of the powder will push the powder down through that hole any better or more constantly????

Perhaps in another brand like a RCBS or similar with a much bigger "hole"??

Rule3 said:

OK, if that works for you but I still question what it really does in a LEE hopper??

Take the hopper off and look at the very small hole in the bottom (plus there is a little ledge) Do you really think that weight on top of the powder will push the powder down through that hole any better or more constantly????

Perhaps in another brand like a RCBS or similar with a much bigger "hole"??

Click to expand...

Thanks for reading/quoting my post.
I understand why you would feel that way.
For me that small hole represents a built-in baffle.
I do think the weight, although very light, does change the dynamics of the Lee pm's and the proof is in my testing results, at least for me.

Your opinion/theories may vary and I suggest you do your own "testing" to prove/disprove them if it is of any further interest to you.

ATLDave said:

If the scale is good to +/-0.1 grains, which would actually be pretty good for a cheap measure, then it can easily seem as though your powder measure is "drifting" by a couple of tenths.

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+1,000!!! I’ve had my PACT scale in use for decades, not the worst but far from a precision instrument. When a charge drifts I re-weigh my initial check drop which is set aside in a glass vial. That, in my mind, eliminates the scale as the culprit.

I have found my Dillon slide bar to be the most consistent over 30 years of trying many others. If I could find a dozen more I’d buy them all but my Hornadys are close enough for most loads. When more consistent results are needed I grab the trickler.

Lyman check weights are good!

https://ads.midwayusa.com/product/1...b415007bfaf93aafa8898c&utm_term=1101100741885

Learned something new from this.. for some reason I never considered that different lots of the same powder would drop different. I'm diligent in checking but more information is always good.

Thanks for the insight

Tilos said:

Thanks for reading/quoting my post.
I understand why you would feel that way.
For me that small hole represents a built-in baffle.
I do think the weight, although very light, does change the dynamics of the Lee pm's and the proof is in my testing results, at least for me.

Your opinion/theories may vary and I suggest you do your own "testing" to prove/disprove them if it is of any further interest to you.

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Whay would I need to test? I have had a L Pro Disc for 100 years and a Auto Drum since it first came out. I also have a Lee PPM an RCBS and a Hornady
I don't have issues with any of them and have some old charts of what every hole for all the powders I use actually drops on the Lee Disc, I don't use it any more and have multiple rotors for the Auto disc with set weights. It works all the time
If you get my "drift"

Erief0g said:

Learned something new from this.. for some reason I never considered that different lots of the same powder would drop different

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Lee devoted quite a bit of time to this and the very reason he sold his dies with dippers to measure powder by volume. If you think about it, that’s all a powder measure is doing; throwing a specific “size” or volume of powder that we then interpret with a scale. Lee’s method scoops from the top where there is no compression and I think if the dippers were more precise in design would be worth using.

I tested a small batch once and accuracy was consistent with what I previously had, but the scale has always been a security blanket I guess so back to powder measures I went. .

Back in 1980 when I first started loading all I had were the Lee Scoops and an RCBS 505 scale. Loaded 38/357 for over 2 years that way and had a lot of fun doing it.

Rule3 said:

Whay would I need to test? I have had a L Pro Disc for 100 years and a Auto Drum since it first came out. I also have a Lee PPM an RCBS and a Hornady
I don't have issues with any of them and have some old charts of what every hole for all the powders I use actually drops on the Lee Disc, I don't use it any more and have multiple rotors for the Auto disc with set weights. It works all the time
If you get my "drift"

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Test to answer what you previously posted: "OK, if that works for you but I still question what it really does in a LEE hopper??"
Testing would answer that question and the reason I suggested it.
I'm as comfortable doing it my way as you are with yours...no issues.
This will be my last post in this back and forth.
Take the last word if you see the need but know I won't be responding to it.
OP, sorry for the continuing drift