Testing a Powder Measure's Performance

[daboone]

I'm old and have 8 powder measures, well soon to be 9 today when the new Lee Classic PM arrives. I say old because I have no excuse but that for having so many measures. But the one thing I found with each measure is they have some powders types they work well with and some they don't. Here is the method a friend shared with me and my own experience to find out just how well the do perform.

By using 3 types of powder, flake, ball and extruded the measure is checked for "powder preferences". This is done by setting the measure for a small charge weight for one test eval and a large charge weight for another. Each evaluation is done by dropping 10 charges and looking at the average.

By doing this I learn what powders are consistent and at what volume, small or large, they stay consistent. Of course other factors are at play in this evaluation like the individual's consistency and method/technique operating the measure. This method assumes the measure is clean and properly preped.
This evaluation doesn't guarantee the results for one type of powder for instance the results gleaned for an extruded powders like IMR4350 it may well be different H4895. But it can let you know what that measure is best with.

How do you check a mechanical powder measure performance?

[Ranch Dog]

How do you check a mechanical powder measure performance?

I do it the same way. I establish a VMD with each powder measure I use with every powder that I will use it with. I drop and average 10 charges. This is more about establishing a VMD but it does establish a track record as to how well the measure is performing with a type of powder.

What I've noticed is that the volume measure between the types of dispensers is a little different. As an example; I have three Auto Disks, four Pro Auto Disks, and two Perfect Powder Measures. When I establish a VMD for a powder, I label that VMD as to what unit it was dropped with. The VMD tends to be very consistent across the type of units but varies against the other types of units. The exception to my previous comments is that the Adjustable Charge Bar typically reflects a VMD similar to the Perfect Powder Measure rather than that of the disks. I have these choices labeled in my personal copy of my VMD Calculator.

VMD_calculator_screenshot_01.jpg

[Patriot007]

Thanks daboone and Ranch Dog, This subject about VMD and powder measures really interest me.
I'm moving into rifle ammo now and just bought a new press. Get this, a Lee Reloader Press, single stage. I mainly bought it for depriming 223/5.56 ammo. I know, I could do this on my load master but its set up for 45acp and working pretty dog gone good, so why mess with it. Just another tool in my book, and I love tools. I'm going to start off slow with this project, and work my way up with it, so get ready for some crazy
questions. Powder measurers for rifle cartridges will be one of them when I get there. Thanks again.