Lee Auto Disc & Unique

[philthephlier]

I wanted about 6.2 grains of Unique in a 45 ACP case for a 230 grain JRN. Lee's data say that disc .66 will throw close to that volume of Unique. I had to go all the way to disc .82 to throw 6.0 grains, a 24% increase in volume to obtain close to the desired charge weight. I double and triple checked the weight on 2 very accurate scales and they both weighed within .1 grains of each other. Could there be a 24 % difference in Unique's volume from lot to lot?

[leadman]

I use the auto disc alot and find I have to use one size larger opening at least. On occassion I have to go up 2 sizes, so this would not be unreasonable.
Powder will gain or lose moisture and this could cause the variance in weight.

Have you checked the weights with a different powder?

[philthephlier]

Posted by Leadman
I use the auto disc alot and find I have to use one size larger opening at least. On occassion I have to go up 2 sizes, so this would not be unreasonable.
Powder will gain or lose moisture and this could cause the variance in weight.

Have you checked the weights with a different powder?

I use the Auto disc with Bullseye, Win-231, & HS-6. All three are thrown accurately within 1 disc up at the most. This is the first time I have had to go up 3 discs to get my weight.

[Colorado4wheel]

They reformulated Unique a little while back. Just trust your scale.

[Love Life]

I use quite a bit of unique with the lee auto disc. 2 sizes up is the norm to get the charge I need.

[Moonie]

I find it best to calibrate your lots of powder, rarely are they exactly the same as the reference data.

Once I calibrate a lot I write down the VMD on the can of powder. Desired grain charge x VMD = CC's

[Cowboy T]

I regularly have to go a size or two up, be it with Titegroup, Bullseye, or 2400. The numbers on Lee's chart seem to be a little high compared to what the powder measure actually drops. I think Lee does this for safety reasons, due to lot variations (better to be a little too light than a little too heavy). +1 to the advice to trust your scale.

That said, yes, all three of my Lee disk powder measures drop very consistently once set, within 0.1gr, every time. That's why I like 'em.

[mooman76]

Yes this is common. The dippers are the same way, in fact I no longer use the chart and just guess and weigh the charges until I find what I can use.

[nes4ever69]

not one of my auto disk holes throw the weight listed, they are either way off or just under what i wanted.

[JeffinNZ]

not one of my auto disk holes throw the weight listed, they are either way off or just under what i wanted.

Ditto. I am making my own chart for the powders I use now. Still love the measure though.

[Artful]

I think Lee does this for safety reasons, due to lot variations (better to be a little too light than a little too heavy). +1 to the advice to trust your scale.

That said, yes, all three of my Lee disk powder measures drop very consistently once set, within 0.1gr, every time. That's why I like 'em.

Yes, Very good powder measure, and this is one reason to buy in larger jugs, or multiple one pounders of all the same lot.