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Old July 6, 2012, 11:08 PM   #1
ScottRiqui
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How do you set up your powder dispenser for a particular charge?

When I'm trying to figure out what size disc(s) to use in my Lee dispenser, I throw six charges, weigh them all together and then divide the result by six.

This has the benefit of reducing the inherent inaccuracy of the scale and giving me a more accurate measure of the *average* charge weight, but the downside is that it doesn't tell me anything about the charge-to-charge variance from the dispenser.

How do you guys do it?
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Old July 6, 2012, 11:30 PM   #2
jcwit
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The way you're doing it is one way. However I set mine and weigh a charg, then throw a couple of charges, then weigh another charg, the repeat. If the charges weigh within what I consider acceptable I go for it. Normally I have little if any varience at all.
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Old July 6, 2012, 11:40 PM   #3
ScottRiqui
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What scale are you using? I have the Lee balance scale, and I sometimes wonder how close to its advertised 0.1 gr accuracy I'm really getting, between having to "eyeball" both the index pointer position and the vernier scale readout. That's why I started weighing six charges and dividing by six in the first place.
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Old July 7, 2012, 12:15 AM   #4
Edward429451
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Whenever I buy a new can or jug of powder I sit down and weigh ten charges and record each charge on a slip of paper, and then apply all the chrony formulas to it. I get the avg, high & low extreme spread, and average deviation from average each throw. Then I tape this to the can of powder for reference when I use the powder.

To set up my measure (RCBS Uniflow), I first zero my scale (RCBS 5-0-5), fill the hopper at least 3/4 full and throw a couple charges to settle the measure and see where I'm at with this particular powder. When I cycle the powder cylinder, I give a definitive tap at the top and bottom (and watch the powder flow through the drop tube thingie), Only one tap top and bottom, with an effort to use the same amount of force for consistency.

I see where I'm at and dial the measure adjustment up or down towards my target weight. After each adjustment of the stem I throw a couple throws to settle it and then weigh the next one. If it is a new load or destined to be something better than standard range ammo, I will take the time to fiddle it to exact as possible considering the variance you will get with different flakes of powder. I refer to the note on the powder and assure that I am getting no more variance than I was getting before.

For example, I have a 180 gr WC load with 5.5 grains of Trailboss. Looking at my note on the bottle of Trailboss, I see that it flows thru my Uniflow with .03 average deviation from average, and with a .2 extreme spread (+- .1), so I try to dial in my measure to 5.5 since I'm not max. That's exact enough for me. If I was riding max then I would target 5.4 (arbitrary) so the most I could get was the 5.5 (or whatever max load.) I like longer barreled pistols so it is very easy for me to achieve high velocity with less than max loads, often starting loads.
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Old July 7, 2012, 12:35 AM   #5
Lost Sheep
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I pick a cavity, assemble the measure, fill to the fullest level I habitually keep it then throw a few charges and dump them into a discard bowl (which will eventually go back into the hopper, but for now they are set aside.)

Then throw a charge and weigh it. Write it down
Throw another charge and weigh it. Write it down
Throw another charge and weigh it. Write it down
Throw another charge and weigh it. Write it down
Throw another charge and weigh it. Write it down

Then doing the same thing as above with the hopper at the lowest level I habitually keep it

Then throw a charge and weigh it. Write it down
Throw another charge and weigh it. Write it down
Throw another charge and weigh it. Write it down
Throw another charge and weigh it. Write it down
Throw another charge and weigh it. Write it down


after the two bunches of 5 charges, if they are all within 0.1 grains of one another I take the average as the amount that cavity will drop, if the two averages are the same.

If they are not satisfactory and reassuring, I throw 5 more and begin to evaluate the average, standard deviation and extreme spread.

I continue like that until I am satisfied with the statistics for my intended purpose for the loads or I am dissatisfied with the stats.

When that conclusion is reached I decide whether or not to use the autodisk for this load or not.

If not, I don't use the autodisk for this load. If I am satisfied, I accept the limitations of the stats and go from there.

If the average is not approaching the load I wanted, I pick the next larger or next smaller cavity and try that one.

If I am trying to get to a VERY PARTICULAR load, I will obtain another disk and ream out the next smaller cavity to make it perform (drop the drop) want. If the powder granules are not shaped so that the drop I want is what I get (different powder granule shapes simply do not perform well in certain measures), I pick another way to mete the powder or switch powders.

I will have to admit that I am not so demanding that I have ever had to do this whole routine, but I am confident it would yield optimal results.

It's a lot of work. For handgun rounds, I have found the Auto-disk to perform adequately without all this fol-di-rol. For long-range rifle rounds, and fine tuning for ultimate accuracy, sure.

Lost Sheep

p.s. A substantial number of handloaders subscribe to the belief that volume is a better determinant of load strength than weight, but that is another debate for another thread.
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Old July 7, 2012, 07:24 PM   #6
dickttx
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It depends a lot on my powder measure and the confidence I have in it.
I now use the Pro Auto Disk exclusively on my LCT. I only use HP38 powder.
I set my scale (the Dillon beam scale) to the charge weight I want.
I pour the measure pretty full and size and prime my first case. I then flair and drop the powder. I pour the powder from that first case into my scale pan and sit it on the scale. It hits zero, so I pour it back into my case and finish that round. Same thing for the next four rounds. I then weigh numbers 10, 20, 40, 60, 80, and 100.
I can't remember the last time it did not throw the weight I wanted.
This does not mean that it throws the amount shown on the chart, but that the throws are consistent with that hole from charge to charge.
I recently wanted a load in between the disk holes so, with some hesitation, I set up one of the adjustable charge bars. To my amazement, it is just as consistent as the disks, even though the bar covers about a third of the drop hole.
I have a new Hornady Lock n Load AP which should arrive Monday. I plan to just move my dies, including my PAD over to the Hornady. Experience my make me want to change to the Hornady powder measure system, if there is something unexpected in the operation of that system with my PAD.
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Old July 7, 2012, 08:06 PM   #7
Turf
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Edward429451 - that's a good idea to tape the charges to the powder - I'm going to steal that one - thanks -
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Old July 8, 2012, 01:56 AM   #8
Mike-Mat
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I have the Lee powder measure. I think it's pretty accurate. The powder can make a difference of course. I was using H335 for my .223 rounds. Everyone said it would meter well, but it's to fine for the Lee disk measuring system. I had powder all ofer the place. Flake and stick powders see to work well. Unique, Bullseye, Benchmark, Universal, Varget all seem to meter pretty consistently.

It's usually +/- 1/2 line on my Lyman scale. I dont have a digital scale. But that's close enough for me. I'm not trying to split the atom or anything.

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