Some time ago I did a measurement survey of my volume measures to see What the differences were for these various measures. Oh, my gosh, it was 19 years ago.
Powder Brand | | GOEX | Granulation | fffg | Code: | 03-77 | 99N001C | | Date: | 20 July 2001 | |
Desired Weight | | 100 | Grains | Measure | 100 | Volume Constant | 0.004031 | in3/grain | 248.047 | | |
Name | Can Valve | Finial | Gostomsky
0-120 Gr | Gostomsky
Settled | Hawken Shop | 70 Gr
Tip | Large
Swivel
0 - 200 Gr | Nikky | Nikky
Settled | Doc's
Swivel
0-120 Gr | Standard |
Diameter | 0.433 | 0.433 | 0.43 | 0.43 | 0.52 | | 0.49 | 0.43 | 0.43 | 0.432 | 0.453125 |
Depth | 3.13 | 2.65 | 2.907 | 2.907 | 1.017 | | 1.982 | 2.75 | 2.75 | 2.909 | 2.5 |
Calc. Wgt. | 100.0529 | 96.79337 | 104.7142741 | 104.7142741 | 99.39849951 | 70 | 92.70854255 | 99.05891 | 99.05891 | 105.7633 | 100 |
Average | 101.22 | 97.08 | 104.95 | 106.64 | 99.05 | 67.18 | 88.54 | 98.24 | 98.96 | 103.58 | 103.44 |
Std. Dev. | 0.722342 | 0.610646 | 0.903388682 | 0.440201974 | 0.748702582 | 0.700476 | 1.534202652 | 0.598517 | 0.414193 | 0.816224 | 0.616802 |
Maximum | 102.1 | 98.3 | 106.3 | 107.4 | 100.3 | 68.3 | 90 | 99 | 99.9 | 105.2 | 104.8 |
Minimum | 100 | 96.3 | 103.1 | 106.1 | 97.7 | 66.2 | 85.9 | 97 | 98.5 | 102.4 | 102.8 |
Conf. Int. | 0.837404 | 0.707917 | 1.04729036 | 0.510322182 | 0.867964157 | 0.812056 | 1.778587312 | 0.693855 | 0.48017 | 0.946242 | 0.715053 |
Lower Limit | 100.8013 | 96.72604 | 104.4263548 | 106.3848389 | 98.61601792 | 66.77397 | 87.65070634 | 97.89307 | 98.71992 | 103.1069 | 103.0825 |
Upper Limit | 101.6387 | 97.43396 | 105.4736452 | 106.8951611 | 99.48398208 | 67.58603 | 89.42929366 | 98.58693 | 99.20008 | 104.0531 | 103.7975 |
I may have been pretty careful in my measurements as I held most of them to less than one grain standard deviation from the selected setting. (68% of my measurements were less than 1 grain.) The confidence interval means that I am 90% confident that the weight of the powder that I measured would be that many grains from the selected weight. The Large Swivel would pour up to 200 grains. In theory I thought I might have needed a lot of powder. In practice that just wasn't the case.
The measure that fit to a valve on a can of powder fit into the measure so the depth of the measure took into account the insertion of the valve into the measure.
The major take aways from all these measurements is that when developing a load for accuracy, use only one measure. My 70 grain antler tip was pretty consistent. Tapping the measure to settle the load will provide a more consistent measurement, but less than 1/2 grain different than unsettled.
GOEX 2fg was a little lighter and closer to the predicted weight compared to volume.