Powder Measures? Whats best.

[David Wile]

Hey Nick,

I cannot begin to understand the physics involved in powder burning characteristics as you described. While it is beyond my personal knowledge, skills, and abilities, I would also submit that most folks on this forum would not be familiar with the burn characteristics you just described. I am not disagreeing with what you said, but I and I think most of us here are mostly ignorant of the very esoteric points relevent to the volumetric powder charges and their use as you described.

If I did not misunderstand you, I think did say that volumetric measuring is dependant on said loads being essentially compressed or slightly compressed so the powder does not move within the case altering the packing density. I have been reloading for more than 50 years, and again I will admit that I am ignorant of the very esoteric points you made in your previous post. However, most of the folks on this and similar forums are also behind the curve like myself, and I would submit that the vast majority of the load made by these folks are not compressed loads and were never intended to achieve the results you describe in the previous post.

Again I will say that I do not "get" the reasons why volumetric measuring should result in more accurate loadings. I would submit, however, that most of the shooters on this forum will achieve more accurate results with weighed loads rather than cases charged by either a dipper or a powder measure. I do not weigh all my loads, and I sometimes use powder dippers to "show off" how one can make loads in the field, but if I want to get the smallest group I can at 100 yards, I will use rounds I made with weighed charges and match bullets.

Best wishes,
Dave Wile

[dsv424]

This has gotten a bit over my limited understanding of measuring powder so I'll just stick to what my main concerns were. Nick you asked what powders I was measuring and I have over 20 different powders and 75% of them are fine. Although,as an example AA-7 and AA-9 tend to leak a lot, and for instance 800X can be somewhat inconsistant getting a precise drop. So I was wondering if different powder measures don't have as much trouble with powders like these?

[David Wile]

Hey dsv424,

Yes, I think you are correct in that this discussion has become a bit over the fence considering your initial question, and I am afraid I have caused some of the problems. I beg your forgiveness, and I will try to help a bit with some basics.

I have had three powder measures (Lyman 55, RCBS Uniflow, and the Hornady measure that came with my LNL progressive press), and they all seem to work the same with different powders. With ball and flake powders, all three seem to be very accurate. However, they are terrible if one is using extruded powders.

You originally mentioned that you have a Lee Classic Turret and that your Lee Pro Auto-Disk Powder Measure is mounted on it. I have never used your press or your measure, so I cannot compare your measure to my measures. I would point out, however, that my Lyman and RCBS measures are mounted on powder stands that I suspect are more solid than your mounting on the turret press. I would also guess my Hornady measure is likely to be more solid on its LNL progressive press than it would be on a turret press. That may or may not be part of your problems.

Best wishes,
Dave Wile

[Unclenick]

Dsv424,

Big flakes like 800X are notoriously difficult to meter evenly. Some suggest with a sliding measure like yours or the Dillon that you attach a fishtank pump to the side of the powder hopper and turn it on for a couple seconds for each throw to settle the powder.

The fine stuff does leak from slide bar or chamber type measures. Somebody described flattening disc edges to minimize this, but I can't find it. No question that a metal drum measure or horizontal rotating chamber measure is best with fine spherical propellants.

For stick powders, the JDS Quick Measure is king. Always within .2 grains. More trouble to adjust than some, but the design really works. The Lee Perfect comes in second for stick powder. The Quick Measure handles fine sphericals without a problem, though, where the Perfect's plastic drum can leak them.


Dave,

To simplify, I was offering two mechanisms whereby a slightly lighter charge of powder with the same volume as a slightly heavier cohort might be expected to produce about the same ballistics. However, I was also speculating that if the first of these mechanisms (burning rate differing due to space between grains differing) is correct, this identical charge volume in consecutively loaded cartridges might not be written in stone? If the powder is loose in the case and you schlep it around Viale Range at Camp Perry, the stuff might shake down and no longer be the same volume inside your cases? If the load is compressed at least slightly, that seemed to me less likely to happen because the grains are jammed against each other, tending to lock them in place. This could matter IF the first part about the bulk density changing in transport is true?

On the other hand, if the second mechanism (particles of unequal size segregating) were the cause, then volume will be king, regardless of subsequent handling. However, it is mainly spherical propellants that have obviously irregular grain shapes and that might be most likely subject to such behavior? The problem with that idea is, most spherical propellants meter so uniformly that it is not at all uncommon for a metal drum measure to throw them within tenth of a grain whether you weigh them or not? My Redding 30BR will throw 748 charges to within about 0.05 grains of one another, for example. I have a lab scale that resolves 0.001 grams, or about 0.015 grains, and that's what it tells me. I also pulled the bullets on 20 rounds of Winchester Supreme match ammo one time and found the same thing. 748 (or close relative) was inside and the charges in these cases had been metered to within 0.05 grains of one another.

The bottom line on all this is that I don't know the superiority of volumetric dispensing holds up under all conditions? Many people don't handle ammunition the way benchrest shooters do. Also, I don't know how many people not shooting benchrest bug holes can really tell the difference even if it does hold up? That's an experiment we can all engage in, but it will be difficult to tell in guns not shooting very small groups because of statistical error masking. (That's a topic I thought of explaining, but I could just see readers dozing off after the first sentence.)

The one story that contradicts the idea that only benchrest shooters will see the difference is Hatcher's tale of working up charges of two powders similar to IMR4320 for National Match ammunition one year. One of the powders had fine cut grains that could be metered to within an extreme spread of 0.6 grains (+/- 0.3 grains) by the volumetric arsenal loading measures of that day. The other was a coarser grain powder that could only be metered to within an extreme spread of 1.7 grains (+/- 0.85 grains) by the arsenal equipment. Despite that wild charge weight swing, the second powder produced consistently more accurate ammunition, became that year's NM load and was used to set several records. One competitor attending the Nationals that year broke some of it down, discovered the large charge deviations, and declared loud and clear to all that would listen what bad ammunition they had that year, somehow failing to pay the new records any mind.

Hatcher surmised that the better ease of flame front movement through the coarser grains was responsible for the superior performance his selected powder gave. He did not attempt to prove it nor did he offer a mechanism to account for its better accuracy. My first speculative mechanism is based on this idea, though, and Hatcher's experience with that varying load would seem to support it. But moving that ammo around Camp Perry clearly did not cause a problem in that year's NM ammunition, which may throw cold water on my thoughts about the charge densities changing or about whether it matters? Of course, I don't know how full the cases in that ammo were and I also don't know if a powder of that vintage had good grain thickness uniformity or not? Too late to find out now.

On the other hand, we still evaluate powder measures based on how uniformly they throw charge weight. The ones that do this well tend to produce more accurate ammunition, AFAIK. So, there we have some conflicting evidence. Such contradictions make this a field ripe for experimentation. I expect one lesson you can take away is that a competitor need not fear that either weighed or volumetric charges automatically inferior.

Nick

[Irish80prf]

Deleted to start a new thread

[Unclenick]

Back in the forum the New Thread button is in the upper left.

[Irish80prf]

Sorry about that I will start a new thread I'm never sure if I should start a new thread for a question like this. Thank you

[oldNewbie]

I've been reloading for my .38 Special for about 4 months now. My equipment includes the Lee Perfect Powder Measure. Powders I have used are Unique, Universal Clays, and Bullseye.

I adjust the measure according to the tables for volume vs. grains in the Lee 2nd Edition Reloading Manual, and instructions for calibration, but it takes considerable tweaking and sometimes a finger-tap or two on the reservoir before dispensing, to get the needle on the Lee Safety Scale right on the mark. Even then, often the needle will be up to 1/4" high or low of the mark.

The manual calls for a starting load with Bullseye of 3.5 grains, and never-exceed of 3.6 - so I am concerned about accuracy of charge.

Can more experienced members help to answer the questions: am I using the wrong measure, the wrong scale, or am I doing something wrong? Is the scale sensitive enough that I am overly concerned about a small variation?

Thanks,
oldNewbie

[Unclenick]

Lee had a warning up about Unique powder not metering well. I can't spot it at the moment. It's also mentioned in this thread. The Perfect works best with short cut grains, like Vihtvuori's N300 series, and coarser spherical propellants. It's better, sometimes significantly better than average with most stick powders. Flakes are just not its strong point, and especially not Unique. But then, I don't know of anything that meters Unique well other than an electronic dispenser. I would guess the Universal, being a rolled sphere, is working best in it? I don't think I've ever tried it in one of mine. They just run stick powders.

[kiwi56]

I had problems with my Hornady powder measure as the level in the powder reservoir dropped the charges got smaller and smaller this only happens on stick type powders. My solution was to to use the powder measure to throw a charge about half a grain short and top up with a trickler and scales.

[Unclenick]

Kiwi56,

You can solve that by adding powder baffles. You can download a baffle template with instructions from my file repository. Look at the double baffle arrangement illustrated. It keeps the fill weight pretty even.

[Jumping Frog]

If you want to see some hard data comparing powder measures, take a look at this article publiashed by LASC Chapter 6.4 Powders And Powder Measures.

It debunks a fair number of sacred cows, and provides the statistical data and standard deviations to support their case.

BTW, there are some powders, such as the previously mentioned Unique, that are just inherently inaccurate in powder measures. When I am selecting reloading components, one of the factors I include in my selection is the powder must be a good metering powder. There are so many good choices out there, why waste my time with something that won't meter when there are ten other choices that will.

[Sevens]

Wow, that was a huge gulp of good reading. This fellow basically did all the different tests that have run through my mind at one time or another while working with my powder measure. (I use a Hornady) He just gathered the tools and took the time to do some real testing.

Seems like he came to some similar conclusions through testing that I did by... ummm... guessing. I figured that some powders would just never measure well, so I don't use those powders. I also figured that it would be a horrible idea to charge cases based on a micrometer setting of a powder measure and not actually weighing the charges it's throwing. With the Hornady, I can removed the cylinder and swap it out for a larger (rifle) metering unit. Simply putting the pistol metering unit in to the exact same place would be a bit of guessing, and that right there would screw up your micrometer "setting."

Looking in to each piece of charged brass is right near the very top of my list of safety items that I will not ever waiver on.

Good reading all around. By the end of the article, I'd almost forgotten the author is in Los Angeles! :barf:

[oldNewbie]

I'm back. Experimentation with flake powders and the Perfect Powder Measure has yielded a couple of thoughts.

I get more accurate throws if I keep the measure's reservoir more than 1/4 full at all times.

I really wish that there were gradations on the scale above and below the pointer giving some idea of how much over or short the charge might be. Like, if the pointer is 1/8" above the mark, is that a negligible fraction of a grain high? The scale claims to be accurate to 1/10 grain, so if the pointer is within 1/8"-1/4" either way, am I good to go?

I reload for .38 Special only at this time, and it seems that anything BUT flake powders is hard to come by, and the cases are rarely half full with any charge in the books. Any suggestions on a nice-metering non-flake powder for a standard .38 load with 158-grain LSWCs would be welcome. That's what I use for targets; for personal defense I use Hydrashock(sp) +P+ factory ammo. I hope I never have to use that.

For that matter, any suggestions on a good measure that will meter flake powders accurately would also be welcome. I really LIKE Unique and Bullseye, and I will use them unless and until I learn of something better.

Eventually I want to move from a single-stage press to a turret press for faster production, and I don't want to have to measure every 5th or 10th load on the scale.

OldNewbie

[m&p45acp10+1]

I have the Lee Perfect Powder Measure. It seems to meter most powders constantly. HI Skor tends not to meter too well in any measure. It is also stated in my Lyman manual in the description of 800X that it usualy does not meter well from most powder measures, and most of the people that use it a lot tend to manualy weigh each charge if they are going for ultra constanat charges.
Oldnewbie I would recomend trying some Trail Boss powder. My measure drops it very contantly. The only concearn when using it is not to compress it. I use it in my .41 mag for general purpose loads for plinking, and shooting the steel knockdown targets. I also use it for fire forming my Wildey magnum brass. It would probably do ver well in .38 spcl. It is also imposible to double charge without it overflowing the case.

[Jumping Frog]

The following article published by LASC compares the accuracy of CH4D, Redding, Harrell, B&M, RCBS, Lee, Hornady, and Lyman 55 powder measures. That powder measure list is in ascending accuracy order (i.e., CH4D most accurate, Lyman 55 least accurate).

Chapter 6.4 Powders And Powder Measures.

[wingman]

(Lee Classic Turret with the Lee Pro Auto-Disk Powder) I use the same setup with very few problems on 45, 40, 9mm, only difficulty is with 380 because powder charge is so small, I use the adjustable charge bar.

If the auto disk is used properly and maintained this setup is fast and no need for batch work. Couple items on measure, check all screws don't over tighten just snug, I clean mine from time to time and run graphite through it, I have checked and rechecked loads and if over 3.0gr metering is excellent with aa5 & Titegroup.

I also have a Lyman 55, it requires maintenance as the Lee measure nor does it measure well at the small end (depending on powder). I use the Lyman 55for rifle loading, batch work.

All tools require cleaning and maintenance plus for accuracy used in a standard motion each time learned with use.

I've tried the dipper method and depending on powder this method can be deceiving, perhaps not dangerous but not accurate either.

[Unclenick]

Jumping Frog,

Look back up at post #37 in this thread.


Oldnewbie,

Just weigh an exact pointer-on-the-line quantity of anything (powder, sand, flour, whatever). Tap it a few times to be sure it is settled. Then move the scale setting down 0.1 grains and see how far away the pointer settles? Tap it to be sure it is settled. Make a mark there. Set the scale to 0.1 grains above your original weight. Tap the scale to be sure it has settled. Put a mark there. Now you'll have calibrated your scale pointer.