[Jimro]

VolusiaJ,

My guess is you are suffering from "artificial precision" in your measurements. Balance beam scales measure to the tenth, because that is really all the precision you need. Unless you have a lab grade scale that measures in grains (something I've never encountered in a lab, they were all metric) your scale is giving you artificial precision.

1. 4.78 gn = 4.8
2. 4.86 gn = 4.9 *
3. 4.84 gn = 4.8
4. 4.84 gn = 4.8
5. 4.82 gn = 4.8
6. 4.88 gn = 4.9 *
7. 4.76 gn = 4.8
8. 4.74 gn = 4.7 *
9. 4.84 gn = 4.8
10. 4.84 gn = 4.8

So you are right at 4.8 grains with the volumetric charge with a standard deviation of less than a tenth of a grain. That is pretty good for volumetric dispensing.

I recommend not using a digital scale, go back to a balance beam scale and do a load workup from 4.5 to 4.9 grains. If your pistol is happy with a 4.8 gr charge, by all means use the volumetric dispencer to load more rounds quicker.

Also, the volumetric density conversion chart that Lee provides is a great place to start, but by no means is it the correct answer. I challenge you to weigh a 20 grain charge of powder, then leave it exposed to damp air for three or four weeks, then weigh that same charge again. I did that with rifle powder and my charge weight (unchanged in volume) had gone up a grain.

Jimro