LEE pro auto disk measure 10% low?????

[sofbak]

More newbie baby steps here with powder measuring....

I have been experimenting with this Lee pro auto disk powder measure all morning! I'm working with trailboss for .45 lc, and some of the proper charges could be done by a double throw of one size disk. I. E., for a 5.6 gr charge, a double throw with the .61 disk should get it, for a 6.0 gr. charge, a double throw of the .66 disk should get it. etc, etc.

Curiously, for every diameter of metering disk for this thing (I've checked .61, .66, and .71), the actual weight of a double throw is coming out right around 10% low from what the manual says they should be-straight across the board. I am taking 11 weight samples, i.e. I throw twice and weigh the charge, do that 11 times and take the average. I've only gotten three sets of data but the under sizes are 89% for the .61 disk, 91% for the .66 disk, and 90.5% for the .71 disk.

I've checked and re-checked to be sure I got the right disc size, and I'm making sure that every last grain of powder comes out of the case and into the scale pan. The measure isn't leaking, and nothing is sticking in the through die either. I can't figure out why they are all low but they are. And I keep checking the scale zero as well. I wonder if the VMD on this powder could have changed by 10%.

Anyone else had this experience. Maybe I hould call IMR and LEE just to see if they have an explanation?

again TIA for all the help.

[epcii]

Well, as a reloader taking all the necessary precautions, it wouldn't make sense to completely depend on Lee's chart of suggested disks anyway. Just find the right one that throws the correct charge you're looking for; regardless of its diameter.

[Flyin Brian]

I just use the chart to get it close, and then weigh a few until I get it where I need it.

If you really need a double charge to get the powder drop you need, why not get the double disk upgrade? It's a lot safer than having to remember to pump the handle twice.

[CalTeacher]

Yes, the disks throw about 10 percent lower than what is listed. Work up to find the correct cavity. If you still can't reach the desired charge weight with the disks then either double pump cavity hat throws half you desired charge or get the double disk kit.

[offdutyalot]

I had this issue myself. The .66 disk throws 5.2gn for me. Far less that the data sheet reads.

A double throw of the .66 disk would leave a heck of a mess, but I'm loading 9mm. I weigh about every 10 throws to make sure I'm getting accurate charges.

[Bill Steele]

It has been a while since I used a Lee Auto Disk, but what I remember is some powders would throw less than the charts said, some powders like Unique threw MUCH less than the chart said, some powders (like W231) threw right on the money to the chart and some powders actually threw more than the chart said it should (not very many in this category). When I was doing it Trail Boss was not on the charts, so I can't tell you specifically, but as others have posted, just use the chart to get close and use your scale to define which cavity to use.

In addition, when you open a new bottle, if you are using max loads, you need to recalibrate as VMD's vary from lot to lot.

Good luck, have fun.

[stand125]

The load charts cover a range. If you look at LEE dies it will recomend a certain disk for a certain range of a particular powder. For instance, a .46 disk will cover say 5.1 to 5.4 of W231 which will cover a 200gr lead and maybe a 185gr XTP bullet. I just have a little note book that I list what each disk will throw with my 2 powders ( W231 and Titegroup ) and even though I have 3 ses of disk, I only use oneset because cavities will vary slightly between disk sets.

[offdutyalot]

It has been a while since I used a Lee Auto Disk, but what I remember is some powders would throw less than the charts said, some powders like Unique threw MUCH less than the chart said,
Good luck, have fun.

I use Unique and I can vouch that this is definately true of Unique and the Auto Disks. My previous posts data was in reference to Unique. I guess that would have helped to note..........

[Bill Steele]

I use Unique and I can vouch that this is definately true of Unique and the Auto Disks. My previous posts data was in reference to Unique. I guess that would have helped to note..........

In defense of Lee, I had read somewhere that Unique had gone through a reformulation, so maybe that is why his charts are so far off. It definitely is fluffier than his charts say.

Then again, I suspect he uses a simple spreadsheet to calulate the drop weights for a given volume, one little typo would throw things off a lot.

[sofbak]

Well, this is a timely seque. The next powder I was going to load for long colt was..................Unique.


I mapped out the listed weight vs actuals for the discs and figured out my loads. Turns out, each disk is between 9.5 and 11% under the listed weights in the Lee chart.

Tomorrow I'll start mapping the unique loads in the same manner.

thanx again for sharing the information.

[offdutyalot]

In defense of Lee, I had read somewhere that Unique had gone through a reformulation, so maybe that is why his charts are so far off. It definitely is fluffier than his charts say.

Then again, I suspect he uses a simple spreadsheet to calulate the drop weights for a given volume, one little typo would throw things off a lot.

I like Lee....I now have 2 Pro 1000s....I actually think that even if the manuals or charts show data (which as we know differ quite a bit sometimes) it's always a good idea to weigh your charge at the beginning of each session and multiple times during.

I'm not confident in calculating volumes and such. I find it easier to ask reloaders I trust and CalGunners for advice. It's what I did when I started recently and was guided safely and accurately and was able to dial in a great recipe for my rounds.

[sofbak]

I like Lee.... it's always a good idea to weigh your charge at the beginning of each session and multiple times during.

Yeah, me too. I spent all day futzing with the Lee scale and squinting at that goofy 0.1 grain poise to figure out these loads. Can't see anything more than a foot beyond my eyes right now.

[Bill Steele]

...it's always a good idea to weigh your charge at the beginning of each session and multiple times during. .

I got so confident with my Autodisk setup, with a load and powder I had loaded before, I would check the weight of the drop once after everything was setup and once when I was done with that batch. The charges only varied as much as the powder I was dropping. Unique varied more than most, powders like Bullseye, AA#9, W231, VV-3N37, etc. never varied more than a tenth charge to charge. The Autodisk Pro is a great design.

[stilly]

I will save you the trouble.
They told me that the autodisks will ALWAYS throw lower then advertised. THAT is how they keep you safe. Want my advice? Go get that CHARGE bar. It is the BEST $10 you will ever spend on the lee powder measure. I ran it for EVERYTHING until I found 4227 powder. Now I know that it is only good up to about 21.5gr but for everything else it works GREAT. Then you can just vary your charge by turning the brass knob.

I swear to gawd that I hate this ****ing keyboard. It is getting chucked tonight...

More newbie baby steps here with powder measuring....

I have been experimenting with this Lee pro auto disk powder measure all morning! I'm working with trailboss for .45 lc, and some of the proper charges could be done by a double throw of one size disk. I. E., for a 5.6 gr charge, a double throw with the .61 disk should get it, for a 6.0 gr. charge, a double throw of the .66 disk should get it. etc, etc.

Curiously, for every diameter of metering disk for this thing (I've checked .61, .66, and .71), the actual weight of a double throw is coming out right around 10% low from what the manual says they should be-straight across the board. I am taking 11 weight samples, i.e. I throw twice and weigh the charge, do that 11 times and take the average. I've only gotten three sets of data but the under sizes are 89% for the .61 disk, 91% for the .66 disk, and 90.5% for the .71 disk.

I've checked and re-checked to be sure I got the right disc size, and I'm making sure that every last grain of powder comes out of the case and into the scale pan. The measure isn't leaking, and nothing is sticking in the through die either. I can't figure out why they are all low but they are. And I keep checking the scale zero as well. I wonder if the VMD on this powder could have changed by 10%.

Anyone else had this experience. Maybe I hould call IMR and LEE just to see if they have an explanation?

again TIA for all the help.

[offdutyalot]

I got so confident with my Autodisk setup, with a load and powder I had loaded before, I would check the weight of the drop once after everything was setup and once when I was done with that batch. The charges only varied as much as the powder I was dropping. Unique varied more than most, powders like Bullseye, AA#9, W231, VV-3N37, etc. never varied more than a tenth charge to charge. The Autodisk Pro is a great design.

I think I'm going to try W231. I've heard nothing but good about it, and like you said, everyone also says it meters excellent in the Auto disks. I'm still learning so I feel the urge to weigh throughout the session. With 9mm and Unique though, I can fill the case and probably be fine. That would probably be about 6.0gr. So, I'm being over-cautious because I don't want to hurt my Glock. I think I'd rather hurt my hand. Plus like you mentioned, Unique does vary a bit and I'd like to know that my charge doesn't drop too low (although my Glock 26 cycled great with only 4.3gr of Unique).

OK, now I'm thread jacking.........sorry.