Dillon PM Drift - problem solved!

First topic message reminder :

OK, everyone now has my permission to call me a dumb-ass, or whatever!

Some time ago a High Master Reloader I know advised me to stop using my trusty 50 year old Lyman Beam Balance and switch to a good electronic scale - good advice! I bought a Gem Pro 250 and it is excellent.

Recently I have been struggling to solve a "drift" problem with my Dillon 650 Powder Measures. I've tried all of the recommended tricks, checked and tripled checked, polished this and that, swapped out the Arredondo Micrometer bar with a HMR supplied bar with a set screw to "lock in" the setting. All to no avail. I kept seeing 0.05 to 0.1 grain "drift" during the course of a session of about 400 rounds.

Today it dawned on me. It is not the PM drifting, it is the scale!

I had got into the habit of taking one shell and setting the scale to zero with that empty brass. Each time I want to check the drop I would put that "zeroed" piece of brass into station 2, pull the lever, take it from station 3 and measure the weight. Today I did that as usual, but something triggered me to check the zero again each time before I put my "zero" brass back in - the scale had "drifted" by 0.05 grains in just a few minutes. I zeroed the brass again, dropped, weighed, spot on. I repeated that about eight times through the course of loading about 400 rounds, every time the drop was spot on!

Aaaarrrggghhhh!!!!

Powder position in the case might have more to do with variance than a tenth or two.

Jon,

You have never in the past sought permission before making fun, why start now?

It is interesting how this thread has twisted and turned quite unpredictably! I guess that is the true beauty of this wonderful forum.

Wobbley, and others. I do get it that, in the 45 at least, minor variations in powder drop are most likely not significant in the overall scheme of things.

But, I've spent a lot of money on high quality equipment and I expect powder drops to be rather consistent. It remains to be seen whether the repeatability of my current set-up continues.

Another lesson learned!

john bickar wrote:

RoyDean wrote:OK, everyone now has my permission to call me a dumb-ass, or whatever!

Is this offer still on the table?

 He may be rethinking that….
+1 on the A/C coming on and the draft causing the digital scale to fluctuate. I can tell nary an applied difference in my score averages shooting CF/45 when loads vary by a couple of tenths. Easy to get lost in the minutae and forget about the true task at hand. My two cents.