Lee Auto Disk - Triple Stack Experiments

[testuser]

Hi there,

I posted here a few days ago looking for feedback on those that have modified a Lee Auto Disk to use three disks I did a few tests today with one .308 case dropping charges of Reloader 15 with the new set up.

The setup...

- Used two 6-32 x 2 screws. These work, but could be a little longer.
- I used a razor blade to cut the tabs off of one side of two spacers.

Price for everything:

Auto Disk Pro Measure = $35
Rifle Charging Die = $10
Lee Double Disk Kit = $10
Lee Double Disk Kit = $10
Lee "C" style press = $25

Previously, I owned a perfect powder measure and found that adding a baffle and sometimes weighting the powder with carriage washers could positively impact accuracy. I like the Auto Disk on my turret press, but found that the round hopper allowed to powder to compact. Going to original square hopper with the baffle and using the adjustable charge bar (so, I don't wear out the threads) fixed that problem.

Those tricks didn't seem to work this time, which surprised me. Especially adding a baffle.

Maybe it's because the measure was mounted to a "C" frame press and not rotating?

Example throw using a 1.09 cc + 1.09 cc + 1.18 cc = 3.36 cc

47.6
47.3
47.4
47.3
47.5
47.7
47.3
47.0
47.2
47.5

Extreme spread was .7 grains, really about the same as my Perfect Powder Measure. I was also looking to throw 46.0 grains of Reloader 15, so this was a little high.

Maybe the additional disk was causing extra error? So, I went to the double disk kit and tried 1.57 cc + 1.57 cc...

44.5
44.8
44.5
44.3
44.7
44.6
44.5
44.6
44.3
44.5

Extreme spread was a little better at .5 grains. Still not much better than the triple disk really.

The next result makes sense, but I wasn't expecting it. I tried 1.09 cc + 1.09 cc + 1.09 cc = 3.27 cc.

46.0
46.0
45.9
46.1
46.3
46.0
46.0
45.8
46.4
46.0

Extreme spread was .6 cc, but it appears to be a little more consistent using the same three disks. A little powder did leak around the disks, which could have resulted in some of the low charges. Next time I might use a screw driver to tighten the screws a little more.

You can still set it low and trickle up. I just use an old spent case to hold the powder, but generally, it will be used for automatic dispensing.

A rotary measure allows for an infinite adjustment, however, I find the Auto Disk has an easy setup and doesn't require and combination of knocks, taps or shakes.




I'll post a few pics when I get a chance. Hope this helps someone out!

[sonnycrockett]

when I stack discs
I get mostly un usable throws,sometimes it does not even dump the powder
I cant figure it out why it acts like this but so far Im at a loss

[Brian Pfleuger]

Interesting results.

The Auto Disk certainly doesn't always behave as I would guess. I have found that using two disks is actually more consistent than one disk. Why? I couldn't guess, but it's been repeatable.

I do suspect that you'd have better results on the turret press. The motion of the dispenser seems to help settle the charges. They come out higher, but more consistent.

[testuser]

Ok, I'm back with more results.

I was thinking more about the powder packing at work today and decided to try the triple stack on my turret press.

First, some observations I've made about using the Auto Disk on my turret press in the past...

I'm mostly a handgun shooter and have loaded several thousand rounds with an Auto Disk and three stage lee press over the last year, year and a half. (I've also owned a Dillon Square Deal and three other presses.)

I found that some powders would compact two to twisting the handle and the vibrations from press operations. Some would be relatively consistent, like Power Pistol, that I use for my 9mm loads. If you didn't operate the press before you measured the powder you'd come up with a low number.

Some powders, never seemed to do that well in the round style pro hopper. AA#9 was especially problematic. It's so fine that it wanted to pack too much when rotating the turret. Even seating the bullets as slowly as I could caused problems. I ended up with too much variation for my taste.

I found that switching to the older style hopper (rectangular type) greatly reduced the packing I experienced due to the built in hopper design.

Now Power Pistol throws almost the same whether I'm operating the turret or not. Blue Dot is the same way and also meters much more accurately. Throws are accurate whether the press is in operation or not at worst I'll pick up 0.1 grains when operating the turret.

Haven't tried ball powder in the measure using the older style hopper just yet...

Using the older style hopper with built in baffle greatly reduced the sensitivity to packing even when purposefully working the handle relatively hard.

That made me think adding a baffle might help the Auto Disk Pro's round hopper.

So, it turns out that Reloader 15 settles in a very even fashion when spun on the turret. Here are my results...

46.6
46.6
46.6
46.7
46.7
46.8
46.7
46.6
46.8
46.8

Throw when not working the press...
46.2

Now that's impressive. All with the same 1.09 cc + 1.09 cc + 1.09 cc configuration as above. Extreme spread was 0.2 grains. That's without using a baffle, rotating three times while pushing up on the ram at a leisurely pace.

So, what about vibrations from working the press somewhat more aggressively?

If you remember the example from above, press vibrations wrecked my accuracy (work smoothly!). Using the hopper with the built in baffle reduces the tendency towards packing due to vibration from seating and crimping at least when using my pistol powders....

Without the baffle...not good...aggressively working the handle threw a 48.0 grain charge. Yikes.

What about after adding the baffle into the round hopper? Work that handle to the stop twice and...well...47.6 and 48.3.

Ok, so adding a baffle seems to be a waste of time.

Conclusions:

- Baffles don't seem to work well for Reloader 15 in my Auto Disk measure. Your results will vary with powder type, I'm sure.

- The triple stack was much more accurate when allowed to rotate on the turret press. It evenly settles the powder.

- Aggressively operating the handle to the stop once or twice could, at best, result in uneven charges. At worst, that extra 1 grain might make a safe load a dangerous one.

- Smooth is fast. Banging on the press can get you into trouble. (I know, I know, beginner stuff, right?)

- Measure your powder after press operations, not before. (It's in the instructions!)

- Powders have different geometries and therefore will pack differently in some measures. (Ball vs. flake vs. short cut stick, etc.)

Hope this helps someone! I'm very happy with my the results and will now use the triple stack on my turret. The "c" style press will now be dedicated to priming using my Auto Prime II.

Question: Why doesn't Lee sell a triple stack kit from the factory???