Lee Auto Disk Inconsistent

DaveTNC

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I've noticed that my Lee Auto Disk doesn't drop consistent loads across mixed brass. I was loading a few 38 Special SWCs this evening and I weighed every charge. Using the .30 disk cavity I was getting anywhere from 2.4 to 3.2 grains of Bullseye, so I started watching headstamps and found that it does fairly good with each brand of brass, but each brand results in a different amount of powder being dropped. 10 Federal cases ranged from 2.6-2.9, R-P was always lower and most inconsistent, with 8 cases anywhere from 2.4-2.7, and 5 Herter's cases gave me a consistent 3.0 grains. (I also had one S&B and one Blazer case which each gave me 3.0 grains, but I only had one of each handy so I don't know how consistent they are.)

So then I tried the .32 disk cavity and loaded 5 each of the Federal, HRTRS, and R-P and got similar results. The R-P was lowest at 2.5-2.7, Federal was 2.6-2.9, and the HRTRS was 4 @ 3.2 and 1 at 3.1.

I watched the Auto Disk and it looked like the disk was sliding completely back and forth. I couldn't see any difference in how it moved with any of the brass. I also noticed that the Herter's and S&B cases were harder to resize and seemed to "stick" on the expander die more than the other brass.

Dies are adjusted per the instructions that came with them, except I only backed the powder through expander die out 2-3/4 turns instead of 3 full turns from touching the shell holder because three turns in the instructions wasn't expanding quite enough to start the cast SWC bullets.

I wiped the outside of the powder hopper with a dryer sheet and couldn't see any signs of static, like powder sticking to the sides of the hopper or anything.

There is minor leaking between the disk and hopper, but it's just a few granules on top of the disk.

Anyone experienced anything like this or have any ideas? Do I have to start sorting brass to get consistent loads?
 
Yep. I have a Redding BR pdr measure, 3 Dillon's and 2 auto drums. The auto drums are the most consistent but if i am loading for match/ultimate accuracy i weigh every charge.
 
I played around with several of them long enough to give up and move on. Pretty much everything works better than the auto-disk, including Lee’s own competing product the Auto-Drum. Even a dipper with some practice will get you there...

Even so, someone will buy it from you
 
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I've been using the same Lee Autodisk powder measure since the late 1980s and it's been very consistent. I guess they don't make them like they used to.

Terry
 
I also have a Lee Auto Drum, and it's been pretty consistent once it had half a hopper or so powder through it. The Auto Disk came with my turret press kit but I've never had much luck with it throwing consistent loads, so I bought the Auto Drum. (This is the older, "non-pro" version.)

A lot of people swear by the Auto Disk (and some swear at it) so I was hoping to get it working so I could leave it on the turret I have set up for 38 Special and use the Auto Drum on my other turrets.

The Auto Disk is probably close enough for the plinking I do as long as I sort headstamps, but that doesn't seem to matter with the Auto Drum.
 
What powder? I have both the disk and drum with no issues with either. I run WSF with the disk
I had decent results with the disc and wsf also. .1 gr variation was ok for light 9mm loads. When I finished off the wsf and went to Cleanshot, it was horrible. It leaked powder everywhere.
 
I had decent results with the disc and wsf also. .1 gr variation was ok for light 9mm loads. When I finished off the wsf and went to Cleanshot, it was horrible. It leaked powder everywhere.

Interesting. WSF is all I've ever ran through mine and it's +/- .1 gr so I don't mess with it.
 
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The saga continues...

So I gave up on the Auto Disk and installed the Auto Drum on the turret, which I thought was more consistent, but here's the results of 25 38 specials I loaded tonight, using Bullseye, with the brass headstamp (H=HRTRS, R=R-P, F=Federal):

3.5H, 3.3F, 3.2R, 3.2F, 3.2F, 3.2F (At this point I unscrewed the adjuster 1/10 turn to increase the load by ~.1) Then I got
3.2F, 3.5F, 3.3F, 3.5F, 3.3F, 3.5H, 3.8H, 3.8H, 3.5F, 3.3F, 3.4F, 3.3F, 3.2F, 3.5F, 3.5F, 3.5F, 3.3F, 3.3F, 3.7H, 3.6H

So, discarding the first 5 before I adjusted the plug on the drum, and assuming I did my math right, the Federal cases ranged from 3.2-3.5 grains with an average of 3.37, and ranges -.17/+.13 from the average. The HRTRS cases ranged from 3.5-3.8 grains, averaging 3.68 grains, for a range of -.18/+.12 from the average. So it seems OK within a brand of brass, but I don't understand why there's about a 0.3 grain difference in the averages between two different headstamps. The drum looks like it's getting the full travel with both brands of cases. I'm being as consistent as I can with the lever pulls, but the HRTRS brass takes more effort to resize/decap and expand.

Looks like I need to load one headstamp at a time and adjust the Auto Drum for each brand.

Is this typical for the Auto Drum? Are there any tips/tricks to try?
 
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What scale are you using to measure the powder? Could it be the cause of you're inconsistencies? I have two auto drums and they are extremely consistent. So consistent that they rarely vary more than a tenth on a ten throw average.

For example, I've been loading 3.85 gr of sport pistol for the last 3 or 4 loading sessions. Haven't changed anything in between so I throw 10 charges in a pan and weigh it, return that to the hopper and then do it again, then verify the weight my digital scale gives me with my balance beam. They are generally within a tenth of a grain of each other.

Then I do my run of ammo, which has usually been 4-500 rounds. When I'm done I throw ten more powder charges in the pan and put it back on my balance beam scale to check for consistency and it rarely ever changes, and if it does it's never more than a tenth or two. Maybe your scale is to blame but if it's not the drum should be way more consistent than what you are seeing especially with bullseye powder.
 
I'm using a Frankford Arsenal DS-750 digital scale. I checked it against my Lee Safety Scale a few times and it always checked out but I guess I should check it again. Come to think of it, I'm not sure how old the batteries are in the digital scale. May try a fresh set and see if that makes any difference.
 
The saga continues...

Is this typical for the Auto Drum? Are there any tips/tricks to try?

These are supposed to be accurate within .1 grain. I have read where people will thoroughly clean the hopper and other parts with alcohol. Allow it to dry and then wipe it down with a dryer sheet to remove any static electricity. Lee recommends the steps below for inconsistent powder charges:

1.) The powder measure hasn’t been conditioned adequately. Run a hopper full of powder through the measure to coat surfaces with powder or dust the metering surfaces with powdered graphite.

2.) Check powder through expanding plug, drop tube and Powder Measure riser for oil residue. Push a clean tissue through to remove any residual oil.
 
This things had several hoppers of powder through it, but I may take it apart and clean it and recoat the surfaces with graphite.

I know it’s worked better in the past because I remember how much better it was than the Auto Disk. But most of the brass I used with it was Federal that I had saved from factory loads up until now, so maybe I just didn’t notice the variation between brands.

So I’ll change batteries in the scale, check it against the balance again, clean & coat the powder measure and powder-through die, and see what happens.

Thanks for the ideas.
 
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