Was considering pulling my sample of Unique out of the stash to try loading in 9mm. Case fill close to 100% and does not leak thru the Lee PPM.
But then weighed a sample from my stash using one of my Lee dippers as a measure, and weight compared to the VMD chart wasn't even close. Got to checking and apparently Unique is notorious for having a lot of variation in weight per volume from lot to lot. So each lot is indeed......Unique?
But out of curiosity, to anyone who has some Unique laying around, what weights do you get using any of the Lee dippers? I used the 2.2 cc.
I'm curious if what I have is so far off the reservation it's not to be trusted.
For safety purposes, the VMD charts yield the charge for batches that are at the maximum density of the powders. Lee says they vary by as much as 16%. You will get lighter charges in most cases if you use the charts This is not explained clearly in LEEs instructions and therefore many consider VMD "useless".
You need to know what the VMD for that particular container is. VMD is a marketing term. We are really talking about specific volume, which is the inverse of specifric gravity (density).
You can make your own chart through trial and error. Not to hard to do with the dippers. But considering the Pro Autodisk has 24 cavities... well, knock yourself out if you wish.
Better to use this method.
https://support.leeprecision.net/en...ng any,(cc) of a single grain of powder (VMD)
Here is how I use VMD:
To pick the correct dipper size
VMD is of the greatest use when dealing with fixed cavity measuring devices such as dippers that have a known volume, such as LEE dippers or the Pro Autodisk. It allows you to avoid using trial and error to pick the correct dipper.
Using it to select the correct cavity size on the Pro Autodisk
For the dippers, trial and error may not be that big a deal, but I find changing cavity size with the Autodisk tedious. You have to empty the hopper, disassemble the measure, change the cavity, reassemble the measure, and refill the hopper each time you change cavity size. I have seen guys on YouTube go through three or four cavities (griping about those “worthless” charts the whole time) before getting the right cavity size.
Using it to set the volume setting of the powder drum before installing it in the Autodrum.
It can also save some time if you are using measure with an adjustable drum like the Pro Autodrum. Use it to select the nearest dipper size and then follow the method in LEE’s instructions for setting the drum before you insert it into the measure. It will get you close enough to make dialing in the exact charge easy.
Determine the % of case capacity filled by a charge
When loading for pistols I like to use a powder that fills enough of the case to make double charge is obvious. Again, you can do this by trial and error, but it’s a whole lot easier to punch a calculator.
