Lee powder dipper variance

[joeblow38]

So I was curious, and did some measurements.
Happens that 1 piece of H414 ball powder is approximately 0.00052cm^3. It has a radius of about 0.5 mm.
I was curious how many pieces of powder were in a 46.9 gr charge, which is the published charge for a 3.1 cm^3 dipper.
Turns out it's about 5920 pieces, based on the calculated average volume / piece, and using a 3.1 cm^3 dipper.
This means that 1 gr is approx 120 pieces. I looked carefully at what 120 pieces looked like, and concluded that indeed this amount could be added \ subtracted from 46.9 grains without a noticeable difference in perceived volume. For fun I compressed the powder charge in the dipper, and indeed there was approx enough space for that 120 pieces. Therefore the dipper technique could easily produce a charge variance of -+ 1 gr. Just the variance in void in the dipper could produce this error. The conclusion is that the dipper is not acceptable for producing a consistent charge.
I will therefore be buying the rcbs 505 balance beam asap. It's accurate to .1 gr, which is approx 12 pieces of powder. This amount would produce a downrange vertical spread of approx. .6 inches @ 450 yards, vs. the 6 inches with 120 piece variance. Therefore any significant vertical spread will be the result of other factors such as shooter, rifle, etc. Therefore I would expect my vertical moa to be comparable to my typical horizontal moa, assuming no \ light wind: 0.5 moa.

 

[ultimate_monkey]

You sir ..... Have far to much time on your hands !

But yes, a GOOD scale is a very wise investment for precision shooting application

 

[duceman]

sounds like your serious about your loading. if so i would skip past the 505 and go with the 10-10 if going beam scale. i can watch change with 1 kernel of h4895 with mine.
when you get your scale; finish your experiment. dip 20 charges and weigh them; with 414 i bet your well under 1/2 grain variance, lee

 

[bobfortier]

I throw each charge less .5 grains, and i finish on the beam scale with a trickler.

 

[Barnes_270]

I throw each charge less .5 grains, and i finish on the beam scale with a trickler.

This. Works very well. Once you've got the powder measure dialed in for 0.3 - 0.5 grains under, you can throw charges and trickle up quickly.

 

[swissinn]

So I was curious, and did some measurements.
Happens that 1 piece of H414 ball powder is approximately 0.00052cm^3. It has a radius of about 0.5 mm.
I was curious how many pieces of powder were in a 46.9 gr charge, which is the published charge for a 3.1 cm^3 dipper.
Turns out it's about 5920 pieces, based on the calculated average volume / piece, and using a 3.1 cm^3 dipper.
This means that 1 gr is approx 120 pieces. I looked carefully at what 120 pieces looked like, and concluded that indeed this amount could be added \ subtracted from 46.9 grains without a noticeable difference in perceived volume. For fun I compressed the powder charge in the dipper, and indeed there was approx enough space for that 120 pieces. Therefore the dipper technique could easily produce a charge variance of -+ 1 gr. Just the variance in void in the dipper could produce this error. The conclusion is that the dipper is not acceptable for producing a consistent charge.
I will therefore be buying the rcbs 505 balance beam asap. It's accurate to .1 gr, which is approx 12 pieces of powder. This amount would produce a downrange vertical spread of approx. .6 inches @ 450 yards, vs. the 6 inches with 120 piece variance. Therefore any significant vertical spread will be the result of other factors such as shooter, rifle, etc. Therefore I would expect my vertical moa to be comparable to my typical horizontal moa, assuming no \ light wind: 0.5 moa.

Amazing!

 

[EC]

This. Works very well. Once you've got the powder measure dialed in for 0.3 - 0.5 grains under, you can throw charges and trickle up quickly.

What they said, I use a 10-10 beam scale in conjunction with a Redding BR powder measure. It is very accurate and once you get the hang of it its pretty fast.

 

[Tcon]

I use an RCBS Chargemaster and throw within +/-0.1gr and double check with a Lyman pro-1000.
I then finish with the trickler. Even with the second check the chargemaster has increased my reloading speed dramatically.

 

[BadAsMo]

I have been around this tree so many times that it hurts my fingers to type it...

I have absolutely no reason to believe that the RCBS Chargemaster or any $200 one decimal place scale is a lick more accurate than your powder scoop. It does give you a precise number on the display but don't confuse that displayed value with the actual value on the scale.

All one decimal place scales that I have tested are actually accurate to plus or minus 0.2 grains!!!

You are FAR better off to spend the cost of the RCBS Chargemaster on a decent 2 or even 3 decimal place scale.

In the end, the load is only as precise as your ability to weigh it. The chargemaster is convenient but not precise and for the cost you can get precise.

 

[supernova]

In practice, the dippers are only good for lighter loads used for cheap plinking fodder. Some powders vary as much as 3 grains with good technique (powder appears level with top of scoop) Trail boss is the only powder I actually dip and it is very consistent in a 3.4cc dipper at 14.5 grs +/- 2 tenths. This works well in my guide gun for soft plinking loads. Most powders are all over the place, especially ball powders. I like my 505 and don't regret it one bit, but is the 10-10 actually more precise? It seems with double the capacity it would be difficult to be as precise with it.