Anybody try this powder measure test?

[Cheapo]

The other night, I did this for the fifth time in my life, with the fourth powder--

I RAN THE MEASURE DRY!! On purpose. Weighing charges as I went, to see if there was any change in charge weight.

This time, it was with H-Universal, in a Dillon measure using the small charge bar. No more variation in charge weight as the measure went empty, compared with normal variations anyway -- +&- no more than .1 grain, with a 5-grain charge.

Well, at least to the second to the last charge. Seated a bullet on the last one, then got about a half-charge in the next case.

SOOO.... the question is: Has anyone else done this and what were the results?

I've done 4064, 296 and now Universal. Only 4064 had much lightening of the powder charge, but only the last five. That was in both an Ohaus measure and a Dillon using the large charge bar. 748, 296, Power Pistol and probably Universal stayed the same all the way to the end.

 

[Monkeyleg]

I did that, but not on purpose. I was loading some .45's using Accurate #5 and was nearly out of powder. The level when I started was just above the start of the green plastic cylinder on my RCBS powder measure. By the time I got to the last couple of rounds I had to rap on the powder measure to get every last flake of powder. Still, the charges measured right.

Dick

 

[labgrade]

If you want to know what you really have. I'd suggest this, to start off:

Weigh one charge (at whatever weight), call it 20.00 grs of anything .... measure this weight & just leave it in your scale pan.

For about 33+/- (33 is the statistical standard) times for record, just pick up your pan & put it back on your scale. Record deviations to see where your scale reads for the same loading - time after time. You may be surprised (or not) at the variability in the scale itself for the same charge ... it's a baseline for any "known" deviations ....

I've spent 20+ years on repeatbilities of machining operations/calibrations/process engineering, etc. ....

 

[Cheapo]

I'll try that sometime, Labgrade.

Certain suspicions arise. But my weighing technique also involves tapping the scale body to get the last 2/10s of a grain or so to settle out.

Yup, it's a balance beam.

 

[yankytrash]

I use an RCBR UniflowII and RCBS Little Dandy, and weigh my powders on a balance beam.

I notice a definite change in powder charge, depending on how much powder is in the hopper. I've concluded that it's definitely due to the pressure weight of the powder in the hopper. I combat the discrepincy by keeping the powder keg close, and keeping the hopper between 1/4 and 3/4 full (depending on the type of powder - I've found long powders need to be more like 3/8 to 5/8). The discrepincy ends up being anywhere around +-.8 grains if I don't my eye on it - that's a lot in some loads.

To keep my balance beam as true as possible, I re-calibrate it after every pound of powder I load up, and I make sure to check it after every 50 rounds (that's how many shells my shell-holder holds). I also make sure to tap the pan lightly to make sure the powder is in a cocentric circle on the bottom of the pan. Although it's still not perfect, the difference is usually only +-.4 grains using this technique.


No matter how you check it, this thread says a lot for shell holders. I cringe at all the posts of beginners with progressive loaders. All those shells flying through there without being able to check them by eye against other shells.
You know - the eye can fool you sometimes when you're only checking one at a time. Consider a man nailing down 40 sheets of plywood on a roof by hand. The first sheet gets nailed every 8 to 12 inches, while the 30th sheet is fine with a nail every 12-20 inches, and the 39th sheet may only get a nail every 18-24 inches at best. Human nature makes us lazy, so keep an eye out.

 

[nwgunman]

Haven't tried this one, but what I have noticed on my Dillon 550 is that if the charge bar is cycled without dumping into a case, the next "dump" will be a couple of tenths heavier than usual. I never load at or near max but it's just something to watch out for. Stay safe.