Mess & Issues with dispensing Accurate #9 from Lee Auto Disk powder measure

[7Acres]

This past weekend I got set up to load some .357 with Accurate #9 for the first time. But after about ~20 loaded rounds I had to switch back to Unique because the fine grained powder of the #9 was proving to be problematic in the Lee Auto Disk powder measure. The clearance between the powder hopper and the sliding disk below had just wide enough of a gap that every time the disk slid to dispense powder the #9 powder rolled between the hopper and disk jamming the disk so much that the spring wasn't strong enough to pull the disk back in like it's supposed to. Plus with every cycle of the powder measure a little #9 would get rolled through the gap and spill onto my press & bench.

Is this just a fact of life with the Lee Auto Disk? Just can't use it with fine-grained powder? If so, I do have an RCBS Uniflow powder measure with the smaller pistol cylinder I could switch to. But how would I incorporate that into my setup? In my four hole turret I suppose I could remove the factory crimp die and move the seating die down to that hole to make room to screw in the RCBS Uniflow directly after the expander. That seems really awkward. Or just leave all dies in place as is, remove the Auto Disk measure and manually hold the RCBS Uniflow over the expander die to dispense a charge. That seems awkward too.

If you were in my shoes and wanted to load your .357 with #9 on a Lee 4 hole turret press how would make it work?

[Frozone]

How old is your auto disk?
They did an upgrade a few years ago that adds a silicon wiper between the hopper and the disk.
It helps a lot but it's not perfect.

[7Acres]

It's about 2 years old. I'll have to check and see if there's any silicon wiper. But I don't believe it has that. If it's an older model I'll inquire with LEE about possibly replacing it.

[VHoward]

I had a Lee Pro Auto Disk powder dispenser when I had the classic turret. It has the silicone wiper and I had the same problem with accurate #5. It is just a fact of life with that powder measure.
http://www.rcbs.com/resources/catalog/rcbs-catalog/
On page 40 of their latest catalog, it looks like they now make expanders to go into the case activated uniflow powder measure to expand the case mouth and dispense powder in one step.

[Norbrat]

I dismantled the Auto Disk and cleaned up any casting and moulding dags. I also removed just a tad of material to reduce the height of the disc cavity/slot, making sure the disk wouldn't bind.

Seems to have helped a lot with leakage. I still get a few granules of powder spilling, but I think that is as much from the open cavity as it comes out from under the hopper.

[john hayslip]

This is a copy of an article by Mustafa Curtess that ran in CBA journal about two years ago and addresses the leakage problem problem and suggests a solution.

"I also favor several ball and flattened ball powders. The problem has been the leakage of very fine spherical powders lie AA#9 (etc) These are like perfect little ball bearings which rolls past the elastic seal as the cavity disk slides from the hopper outlet to drop tube.
A close look shows excessive clearance between the moving disks and the fixed surface of the meter body and powder hopper, which does not compress the elastic seal sufficiently to contain the dine powder grains.
The powder hopper sits on vertical castings on both sides of the disc, and reducing the height of those "walls" reduces the excessive clearance.
All disks look deceptively casual.
they are in fact high precision injection molded items which vary only between .445 and .450 thick among the 60 or so disks I have accumulated.
The surfaces to be reduced can be filed or possibly milled to the correct eight, but inverting the meter body on a sheet of 220 grit abrasive paper and running it across the sheet evenly will do the job easily. Check your work frequently with a disk in place and a straight edge laid across the meter body and disk. Only remove enough material so the straight edge barely touches the disk.
I first attempted to leave a clearance to avoid binding, but the graphite left behind by the powder is lubricating and all moving surfaces are mirror smooth. So long as light cannot be seen between the assembled disk and hopper, the reduction is sufficient.

Before reporting on this modification, I deliberately altered one just enough to bind. This was more difficult to achieve than I expected. The return spring is very strong and the working surfaces are very smooth. When I got the desired effect there were three simple solutions: a thin coat of epoxy on the abraded surface, a thin paper washer around the mounting screws (my intervention here but I find cigarette rolling paper to be reliably .001 thick), and best merely leaving the knurled mounting nuts a bit loose."
There is a little more to the article that I edited to save typing and if you want a copy send me a snail mail address by pm and I'll send you a copy.

[7Acres]

PM sent. Thank you John Hayslip!

[Moonie]

I have 2 of these, one was an older body and had more space than the newer pro version. I updated the older one with the pro version update kit and sanded down the body until there is the same clearance as the new pro. I no longer have issues with H110/W296.

[JonB_in_Glencoe]

7Acres' text in black

...Is this just a fact of life with the Lee Auto Disk?
YES

...Just can't use it with fine-grained powder?
you need to get a Lee "PRO" auto-disk measure...it functions Much better/won't jam ...like the standard auto-disk, But the "PRO" still leaks a little, especially when the case sticks to the expander leading to the powder measure "jumping" when the case releases from the expander.

If so, I do have an RCBS Uniflow powder measure with the smaller pistol cylinder I could switch to. But how would I incorporate that into my setup?
you need the perfect adaptor (no financial interest)
http://www.uniquetek.com/site/696296/product/T1370

Good luck,
Jon