Seismic Sam wrote:Well, the fact of the matter is that most any powder scale has some variance, and while the Lee Perfect Powder measure has a micrometer system which changes the powder chamber volume in increments of .01 cc, which is plenty good enough, the fact of the matter is that the powder that falls into that chamber and stacks a little bit different every time, and the volume when thrown depends on how many seconds the measure is allowed to sit with the powder draining down into the micrometer tube, so there's a substantial difference between 1 second to fill the tube and letting it sit for 5 or 10 seconds. To say it another way, you want to go from handle up (charge tube filling) to handle down (dump) and back to handle up. (fill) By the time you get that powder weighed or into the case and have grabbed another case, the powder has had a few seconds to settle. If you go handle down to up and then back down to dump it into the case, the time filling can be less than a second AND variable, depending on your individual throw, and that will most DEFINITELY affect the amount of powder thrown.
And second, powder is somewhat like a compressible liquid, so you get more powder in the tube when the hopper is full, and less when it's nearly empty. Some measures are worse than other in this respect. Bottom line, if you want accuracy or are loading max loads, you better be weighing EVERY charge that you throw anyway. Small ball powders like 231 pack pretty uniformly, flake powders like Bullseye less so, and then big granules like Retumbo even less that that, and the strength with which you rap the throw handle in the up or down position will also affect charge weight. Vibration makes powder settle and become more dense, just like concrete.
I have been attempting to be consistent with my operation of the the powder measure, but I don't think mine has broken in yet. It is still a little stiff and sticky, which makes it difficult to be smooth. I have found using the baffle helps a bit, but not as much as I would like. In the future I think I would like to get a progressive press for bulk reloading target loads, but as it stands I don't think I would trust the powder measure I have with any sort of consistency.
I have noticed some differences in the way different powders drop. What I am beginning to realize is I need to start keeping a log of this type of information, as it will probably add to my efficiency and enjoyment of reloading.
As far as Rugersol's comment about keeping the measure tight. I have hand tightened the measure as much as possible, and it still seems to move. Is using the vice grip going to far?
