Problem with Lee Pro Auto-disk Powder Measure

[10gaOkie]

I have two Lee Pro A-D powder measures and they have been fine loading Bullseye 3.0 to 5.0 pistol loads with my Lee 1000 presses. Now I am wanting to set up a Lee Turret press to load .351WSL. After trying 17.0gr load of both 2400 and IMR4227, I cannot get that Lee measure to throw accurate charges for anything. My powder drops vary + or - as much as one half grain. I have tried both measures with both the fixed disks and the adjustable disk with no success. During my testing, I tried the same loads with my RCBS Uniflow and all is well, it will drop the desired charge every drop. Is it normal for the Lee to act this way? Also, is there a die made that I can adapt my Uniflow to the Lee Turret? /Chris

[farmerjim]

I have never had any problem with the Lee auto-disk and IMR4227, I have never used 2400 in the auto-disk. I have never had any problems with any of the powders I have loaded with the Lee
Auto-drum.

[Eddie17]

I would think 1/2 grain should be acceptable until you get into very small loads.
1/2 grain could also be a measuring tollance on the scale your using.
My 2 cents.

[10gaOkie]

I checked dropped charges with both my balance beam and my RCBS Rangemaster750. Sometimes the drops are off as much as + or - one grain but not often. The normal variation is one grain. This is with my Lee Auto-Disk, not the auto drum. Checking drops with my RCBS Uniflow, they are 100% on the money. Both measures side by side. Small pistol charges are +- one tenth gr. with the Lee. no powder leaks.

[rtracy2001]

I get very good consistency with 2400 with the Auto Disk Pro on my Loadmaster.

I assume that your Uniflow is mounted in a stand and not on top of the turret press?

If so, the problem may not be with the Auto Disk measure, but the press. The pro 1000 (and Loadmaster) securely mounts the powder measure and moves the cases beneath it. The turret press keeps the case in one spot and rotates the measure around it, usually giving it a good shake in the process. The problem is, it doesn't shake it the same every time. I could never get my Auto Disks measures to mount securely onto the charge die (no flop/slop) when using the turret press, there is always some slop because of the way it works. With the measure flopping around with every pull of the handle, I couldn't get anything like a consistent charge. Between that and the safety prime system on the turret press, I was happy to upgrade to the Loadmaster.

Another possibility is that you are using different disks and they just haven't had time to build up enough graphite from the powder to dissipate the static charge. Long shot, I know.

[10gaOkie]

The auto discs are mounted on my two Lee 1000's. They do fine. The ones I tested that were inconsistant were mounted on my Lyman Tmag turret press. There is no vibration with it.

[country gent]

With the lee auto disk 17 grns may be getting to the upper end of its range in volume. I have found most measures are their most accurate in the mid range of their range. Also with the auto measures play and or wear can make a big difference in how they operate and their accuracy.
Make sure the measure is making travel stop to stop. Not just short of it on either end, this affects drop and fill leaving a small ledge to hold powder. Clean the measure good and look for wear loose parts.

[dragon813gt]

I would think 1/2 grain should be acceptable until you get into very small loads.
1/2 grain could also be a measuring tollance on the scale your using.
My 2 cents.

.5 grains is not acceptable. Pretty sure you're thinking of .05 grain as being acceptable. The PAD should throw the same charge every time. The only issue I have w/ mine is leaking fine ball powders like H110/W296. Even w/ it leaking it still throws the same charge every time.

[z28z34man]

I have never had a problem with either of my auto disk or my auto drum. What size hole are you using? Have you tried the double disk kit?

[Moleman-]

Check the rubber wipe for a burr caused by rubbing on the disk. Had mine start dropping inconsistently and traced the issue back to that. The burr would occasionally trap some powder so I was getting light charges. A few seconds with an exacto knife removed the burr then it was back to it's normal self.

[10gaOkie]

Thanks guys for your thoughts and ideas. They have helped me narrow down my possilble problems. I did another test session last night with better results but still not good. I just wanted to make sure the Lee disc measure would give me what I need before ordering parts and turret press to make the set up. In using what equipment I already have on hand, I think is most of the problem. I dont have the correct linkage and spring for the auto pro. Both of mine are set up to operate with a chain as they were used on 1000 presses. Next, I dont have the correct drop tube and was using the 45 acp tube. If I had thought to use 45 brass for drops, that might have helped. In short, most of the problem points to the amount of disc travel is not consistant, not having the right linkage and spring. /Chris

[Moleman-]

I've converted one or two of the older rectangle hopper pull chain type over to the spring/case activated type with the newer round on/off hopper. It's basically changing the steel arm and adding the spring. The Zinc collar that breaks every 50k rounds or so might also need changed and I seem to remember changing one of them but it was on an older chromed disk measure I was converting. Take a look at the links and if your "swivel adaptor" looks the same then you don't need it. Mine seemed to be more consistent and basically trouble free after ditching the pull chain. Lee has the parts, as usually does Midway. I use Lee die sets and just screw my auto pro's into the top of the powder through expander die.
From Midway.
The lever https://www.midwayusa.com/product/543877/lee-auto-disk-powder-measure-lever-replacement-part

The spring https://www.midwayusa.com/product/334897/lee-auto-disk-powder-measure-spring-replacement-part

The collar/swivel that you may or may not need https://www.midwayusa.com/product/547368/lee-auto-disk-powder-measure-swivel-adapter

[10gaOkie]

Did you get the same accuracy in powder drops from the square hopper measure as you do with the new pro model? I have got to add another one, should I stick with the pro model?

[Moleman-]

I'd stick with the pro model as it gets you the rubber wipe grommet and the powder shut off. The base casting is the same between the models, it's just the lever, swivel and powder hoppers that are different. Set up properly they're pretty accurate, but if you're wanting bench rest accuracy you'll end up being disappointed. I have the double disk kit but generally just use a powder measure if the capacity goes over what the large disks or adjustable disk can do. I've only used mine for 9mm, 38& 357, 40&10mm, 44mag/special, 45acp, and with the double disk kit 223, 762x39, 6x45. The double disk kit only allows a limited number of powder choices/charge weights which becomes more of an issue with rifle cartridges.

[Grmps]

Sounds like the powder measure needs a little vibration to be consistent. I wired in a cell phone vibrator to my auto disk with a switch that vibrates the measure for 2 seconds on every stroke and theat help emesly in getting even charges

There are some you-tube posts for leveling/polishing the auto disk powder measure and wiring a cellphone vibrator with a switch.
.
*sorry, I don't/can't risk linking to youtube anymore*

[Eddie17]

I will say 1 more time, is the scale you are using precise and or certified to within a 1/2 of a grain?
Moving out to 1/10 of a grain, again is your scale able to measure this small amount?
These are very small variances, is the scale you are using able to measure these amounts?
My 2 cents,
Eddie17

[Kenstone]

I've converted one or two of the older rectangle hopper pull chain type over to the spring/case activated type with the newer round on/off hopper. It's basically changing the steel arm and adding the spring. The Zinc collar that breaks every 50k rounds or so might also need changed and I seem to remember changing one of them but it was on an older chromed disk measure I was converting. Take a look at the links and if your "swivel adaptor" looks the same then you don't need it. Mine seemed to be more consistent and basically trouble free after ditching the pull chain. Lee has the parts, as usually does Midway. I use Lee die sets and just screw my auto pro's into the top of the powder through expander die.
From Midway.
The lever https://www.midwayusa.com/product/543877/lee-auto-disk-powder-measure-lever-replacement-part

The spring https://www.midwayusa.com/product/334897/lee-auto-disk-powder-measure-spring-replacement-part

The collar/swivel that you may or may not need https://www.midwayusa.com/product/547368/lee-auto-disk-powder-measure-swivel-adapter
I never liked the mechanical motion of the wrap around spring on the pro auto disc, I just use the chain arm/lever and use a spring rather than the chain.
208898
It's much easier to disconnect the spring and throw a charge manually too[smilie=s:

I'm thinking this setup will work on a turret :coffeecom
On my RCBS Piggyback press I had to use 2 risers so the pm cleared the index rod, so I put a hose clamp on the sizing die and hooked the spring to it :razz:.
This could work on a turret, or find another point to anchor the spring on the turret so that it indexes with it.
208899
:mrgreen:

[Kenstone]

I have two Lee Pro A-D powder measures and they have been fine loading Bullseye 3.0 to 5.0 pistol loads with my Lee 1000 presses. Now I am wanting to set up a Lee Turret press to load .351WSL. After trying 17.0gr load of both 2400 and IMR4227, I cannot get that Lee measure to throw accurate charges for anything. My powder drops vary + or - as much as one half grain. I have tried both measures with both the fixed disks and the adjustable disk with no success. During my testing, I tried the same loads with my RCBS Uniflow and all is well, it will drop the desired charge every drop. Is it normal for the Lee to act this way? Also, is there a die made that I can adapt my Uniflow to the Lee Turret? /Chris
Uniflow Adaptor
https://www.amazon.com/Pistol-Adapter-RCBS-Lyman-Measures/dp/B0041OJAJS
Not case activated though :cry:

[gwoz]

Recently my Lee Auto Disk .380 ACP settup has been putting a small (1/16 inch wide) fold on the case mouth. Happens about 1 out of 5 or six cases.

[Messy bear]

Some good ideas in this thread. Thx guys

[Moleman-]

I never liked the mechanical motion of the wrap around spring on the pro auto disc, I just use the chain arm/lever and use a spring rather than the chain.
208898
It's much easier to disconnect the spring and throw a charge manually too[smilie=s:

I'm thinking this setup will work on a turret :coffeecom
On my RCBS Piggyback press I had to use 2 risers so the pm cleared the index rod, so I put a hose clamp on the sizing die and hooked the spring to it :razz:.
This could work on a turret, or find another point to anchor the spring on the turret so that it indexes with it.
208899
:mrgreen:

The wrap around spring does look like it would fail quickly, but it took over 100K rounds to break the first one. Think I'd replaced the zinc sleeve/collar thing twice by then. The sheetmetal eared washer piviots back and forth every time you take the measure on/off of a die and will eventually cause the sleeve to crack right there. I keep an extra collar and spring on hand just like I keep extra press parts and decapping pins. I like your adaptation and it looks like you could likely use an easily available spring from ACE. For other presses if you wanted to get fancy you could likely take a piece of 1-1/8" steel strapping, drill a 7/8" hole in it for the die and make a bend far enough away so the die lock nut will turn for an attachment hole. Or go a little thicker and thread it and put it above the lock nut if it doesn't clear the press.

[Kenstone]

The wrap around spring does look like it would fail quickly, but it took over 100K rounds to break the first one. Think I'd replaced the zinc sleeve/collar thing twice by then. The sheetmetal eared washer piviots back and forth every time you take the measure on/off of a die and will eventually cause the sleeve to crack right there. I keep an extra collar and spring on hand just like I keep extra press parts and decapping pins. I like your adaptation and it looks like you could likely use an easily available spring from ACE. For other presses if you wanted to get fancy you could likely take a piece of 1-1/8" steel strapping, drill a 7/8" hole in it for the die and make a bend far enough away so the die lock nut will turn for an attachment hole. Or go a little thicker and thread it and put it above the lock nut if it doesn't clear the press.

Take a close look at the sleeve where the lever arm contacts it, it's a knife edge, something I rounded off to get a smoother action.

That and the lever being a stamped part also has a knife edge where it contacts/activates the sleeve.
The edge of a stamped part (lever arm) has one 3rd of it's thickness as shear and two 3rds break and is never 90 degrees.
That's another edge I stone smooth and perpendicular for a smoother running measure.
It never hangs up anymore.
Rigged like this I can easily disconnect the spring and hand throw a charge to weigh.
I actually throw 10 charges and take an average.
228569
:mrgreen: