Lee Pro Auto Disk Testing

[Enfield47]

[MR_X]

I have no issues with the Lee Pro Auto Disk. In fact I use it instead of the powder drop system that came with my LnL for Varget. I get consistent drops on it. What I did instead of using the disk size Lee's chart suggest to use, I use 2 disk with the same size hole (or as close as possible). With Varget 2 disks of the .88 size gives me a perfect 23.5gr drop 8 out of 10 times.

[sofbak]

It is possible to use the Lee adjustable charge bar with the double disk kit with a couple of restrictions/safety considerations.

The adjustable charge bar will only mount on top of the fixed diameter disk, not under it.

Be sure that the cavity size in the adjustable charge bar is smaller or of approximately equal size as the fixed diameter disk below it. You don't want to create a "shelf" between the charge bar and the disk below that could lead to an over charged round.

It may take a bit of trial and error to find the right combo, but used as described, the charge bar may allow you to fine tune a load if a pair of fixed disks doesn't get it.

[BruinGuy]

It works and works well once you get it dialed in, even with the double disk.

What I don't like is having to take it apart, try the disks, find out the load isn't where you want it, take it apart again, try a different combination, etc. Lee's data is, in my experience, very inaccurate, which is frustrating. Of course, the powder situation doesn't help, so the disk combo that worked for one powder is useless for the next.

I only use it for rifle now if I'm doing a big batch. I still use it for pistol and it works great, but for rifle I usually just put a funnel on top of my rifle powder through die and drop with my regular powder measure if I'm doing 200 or fewer rifle loads. I wish there was a way to mount my manual "Perfect" powder measure on top of the rifle powder die...that would be pretty sweet!

[sofbak]

It works and works well once you get it dialed in, even with the double disk.

What I don't like is having to take it apart, try the disks, find out the load isn't where you want it, take it apart again, try a different combination, etc. Lee's data is, in my experience, very inaccurate, which is frustrating. Of course, the powder situation doesn't help, so the disk combo that worked for one powder is useless for the next.

I only use it for rifle now if I'm doing a big batch. I still use it for pistol and it works great, but for rifle I usually just put a funnel on top of my rifle powder through die and drop with my regular powder measure if I'm doing 200 or fewer rifle loads. I wish there was a way to mount my manual "Perfect" powder measure on top of the rifle powder die...that would be pretty sweet!

This was my initial experience too. Which is why I invested $12 in the adjustable charge bar. Saves a ton of time, and you can dial in any load weight you want (within the min/max range limits), instead of "accepting" the weight delivered by the closest diameter disk.

[MR_X]

It works and works well once you get it dialed in, even with the double disk.

What I don't like is having to take it apart, try the disks, find out the load isn't where you want it, take it apart again, try a different combination, etc. Lee's data is, in my experience, very inaccurate, which is frustrating. Of course, the powder situation doesn't help, so the disk combo that worked for one powder is useless for the next.

I only use it for rifle now if I'm doing a big batch. I still use it for pistol and it works great, but for rifle I usually just put a funnel on top of my rifle powder through die and drop with my regular powder measure if I'm doing 200 or fewer rifle loads. I wish there was a way to mount my manual "Perfect" powder measure on top of the rifle powder die...that would be pretty sweet!

In my Lee instruction buckler, it states that Lee's data is on the low side so I usually go one size up from what they suggest. Some times it works, some times I have to keep tinkering.

[BruinGuy]

$12! That's outrageous!!

I know, I've been meaning to pick one up for months now. It's still a pain to swap out disks though, especially with the long screws for the double.

[Nirrad]

I wish there was a way to mount my manual "Perfect" powder measure on top of the rifle powder die...that would be pretty sweet!

There is! You need to get the Universal Powder Die, I recently switched to this for 223 on a Pro 1000 and it's nice. I gave up on the combination of disks - too time consuming. But sounds like OP is getting good results.

[wc12]

It works and works well once you get it dialed in, even with the double disk.

What I don't like is having to take it apart, try the disks, find out the load isn't where you want it, take it apart again, try a different combination, etc. Lee's data is, in my experience, very inaccurate, which is frustrating. Of course, the powder situation doesn't help, so the disk combo that worked for one powder is useless for the next.

I only use it for rifle now if I'm doing a big batch. I still use it for pistol and it works great, but for rifle I usually just put a funnel on top of my rifle powder through die and drop with my regular powder measure if I'm doing 200 or fewer rifle loads. I wish there was a way to mount my manual "Perfect" powder measure on top of the rifle powder die...that would be pretty sweet!

I have a theory that I have not tested out and just want to share it.

1. Find out the "actual" powder VMD. I would calculate for the actual VMD based on the disk I use and here's how I would do it. Use a disk/disk combo and weigh the powder coming out of this combo. Divide the value of the disk/disk combo by the resulting weight of the powder. The result is the "actual" VMD. Of course I would check the weight a few times to get an average of the resulting weights to get a more accurate VMD.

2. I would use this actual VMD to multiply the desired powder charge in grains. The resulting number, would be the size (in cc) needed to throw that amount of powder.

This will at least eliminate the trial and error portion and changing out the disk too many times. I have not tried this myself cause I'm too lazy, but if someone does, please tell me if it helps.

[sofbak]

I have a theory that I have not tested out and just want to share it.

1. Find out the "actual" powder VMD. I would calculate for the actual VMD based on the disk I use and here's how I would do it. Use a disk/disk combo and weigh the powder coming out of this combo. Divide the value of the disk/disk combo by the resulting weight of the powder. The result is the "actual" VMD. Of course I would check the weight a few times to get an average of the resulting weights to get a more accurate VMD.

2. I would use this actual VMD to multiply the desired powder charge in grains. The resulting number, would be the size (in cc) needed to throw that amount of powder.

This will at least eliminate the trial and error portion and changing out the disk too many times. I have not tried this myself cause I'm too lazy, but if someone does, please tell me if it helps.

the problem with the auto-disk set up is that the disk cavity never completely fills up. Because of settling, and a bulk material property called "angle of repose", there is always some volume of the disk at the top around the perimeter that does not fill-unless you shake the press really good to cause some mechanical compaction/settling of the powder in the cavity.

And the amount of settling or the "not-filled" portion of the disk cavity will vary a little from one diameter to the next.

So you might get an accurate "practical VMD" but it won't be the true VMD. I just took note that depending on the powder being used, my auto-disk set up would under-deliver between 3 and 6% of that specified in the Lee manual, and then did the trial and error routine to find the closest cavity for the charge I wanted-at least I did until I invested in the adjustable charge bar-get one and be done

[wc12]

the problem with the auto-disk set up is that the disk cavity never completely fills up. Because of settling, and a bulk material property called "angle of repose", there is always some volume of the disk at the top around the perimeter that does not fill-unless you shake the press really good to cause some mechanical compaction/settling of the powder in the cavity.

And the amount of settling or the "not-filled" portion of the disk cavity will vary a little from one diameter to the next.

So you might get an accurate "practical VMD" but it won't be the true VMD. I just took note that depending on the powder being used, my auto-disk set up would under-deliver between 3 and 6% of that specified in the Lee manual, and then did the trial and error routine to find the closest cavity for the charge I wanted-at least I did until I invested in the adjustable charge bar-get one and be done

That's the reason I'm too lazy to try it out 'cause I have a charge bar.

[Enfield47]

I'm going to have to get a charge bar. It sounds like it will greatly simplify the process. Can you adjust it without having to remove the powder dispenser?

[sofbak]

I'm going to have to get a charge bar. It sounds like it will greatly simplify the process. Can you adjust it without having to remove the powder dispenser?

To adjust it all you do is turn the brass knob on the front of it- no need to remove anything. Need a larger charge? Turn the knob clockwise. Need a smaller charge, turn the knob counter clock wise. Do a couple of "check throws" to verify weight, and go.

[Fishslayer]

the problem with the auto-disk set up is that the disk cavity never completely fills up. Because of settling, and a bulk material property called "angle of repose", there is always some volume of the disk at the top around the perimeter that does not fill-unless you shake the press really good to cause some mechanical compaction/settling of the powder in the cavity.

This is handled by the "clunk" of the indexing turret.
The manual says to run the press several cycles to settle the powder, too.

[sofbak]

This is handled by the "clunk" of the indexing turret.
The manual says to run the press several cycles to settle the powder, too.

Yup, that helps a lot.. And the more consistent your hand motion on the ram handle gets, the more consistent the dropped charge weight gets....

I also discovered another "kluge" that helps. Once while I was dropping Unique, I noticed after about 30 rounds that every drop was dead on equal on my scale. Normally unique delivered a wide deviation of weight, and I was perplexed about what I had done to tighten up the consistency.

I noticed that the powder hopper had rotated just a bit off center of the turret, and on the turret rotation to the bullet seating die, the side of the hopper was lightly bumping the primer tray on the safety prime attachment.

So after straightening and securing the powder hopper, I rigged up a stationery "thumper" that the hopper would run into (gently) once every full rotation of the turret. this thump made a big difference in tightening the weight deviation on all powders, and saved some wear and tear on my safety prime too.....