Using an Autodisc for Unique

[jdmick]

I'm curious how many here use a Lee autodisc type measure for Unique. I just started using mine (non pro) to drop 5.4g for .38 Special and it drops within .1 of a grain every time I've checked (a total of about 20 times). I have to say I'm comfortable using it now but is this something that will bite me in the a$$ at some point. Maybe one drop bridges and you get a double charge on the next. I've got a light set up above the cases to try and catch something like that but mistakes happen.

[CrustyFN]

You only have to worry about the powder bridging and getting a squib load. It can't double charge because the cavity is set for a certain amount and won't let more than that in. As long as you are using the disks that came with it you should be OK. The adjustable charge bar and Unique don't get along with smaller loads. The light so you can see the charge before you set the bullet on is a great idea. I have done the same thing since the time I had to pull 93 bullets.
Rusty

[benedict1]

CrustyFN is right. At the volume you are dropping you should continue to get excellent results. As the nylon bushing gets broken it, rubbing against the disk with each charge, you'll reach ±0.05 gr accuracy.

It is only when you get down below 4 gr. of Unique, or any flake powder that you have to watch it. Then, Lee recommends rapping the powder measure with a screwdriver handle. Static charges on flake powders can get worrisome too and at low weights you may experience light charges.

I load 4.7 gr of Unique with 124 gr bullet in 9mm and have turned out thousands of them. Most enjoyable, no problems. When I check the occasional charge weight it is usually smack on 4.7 gr.

Ball powders are even better. I shoot 2.2 gr Win 231 in an old S&W .38 S&W revolver--it throws 2.2 gr every time. You don't have near the problems with bridging or static with ball powders.

If you really want to make light loads find a ball powder that will do what you want.

Same thing goes for the adjustable bar, but it is even more cranky since it is designed as a narrow slit cavity, not a round hole. I wouldn't trust it with Unique below about 4.5 gr. With ball powders it should work pretty good.

[jdmick]

Thanks for the helpful replies. I wasn't even going to try Unique in the auto disc since I recall hearing how poor it measures. I must live right since it burns clean for me too. I've got an adjustable charge bar coming next week but I'll just stick with the regular discs for Unique.

[Nortonics]

Excellent & factual info above.

Lee adjustable charge bar - very flexible for medium size handgun type loads where you adjust for the exact drop you're looking for - you'll like it.

[Mike Irwin]

The larger the hole in the disk, the more repeatable the charge weight is going to be. That's true with pretty much all flake powders.

I was using my Lee disk measure with Unique to reload .32 Long ammo many years ago. At something like 2.0 grains of Unique I was getting HUGE variations in load weights.

That's pretty much when I gave up on Unique. 231 was my standard, and it measured great no matter what the size of the hole in the disk.

[willr]

Lee reloading manual says that for flake powder the Autodisc should not be used for volumes 0.4 cc or less. I tried it for 4 gr of Unique and got great variations in charges.
willr

[amamnn]

I made some modifications to my pro auto disk some time back, and have been getting good results using unique in it until recently. Though Lee claims the measure does not need a baffle I fitted one and it helped tremendously. I've been using it to load everything from a .32 acp to a .357 mag, so the powder drops varied. I was especially careful to check the smaller drops quite often and never caught one grossly undercharged. So, I figured I would only need to check the bigger drops every 6 to 8 rounds or so and I would be ok. I was wrong. I now use my PACT dispenser/scale to load everything.

I am not sure how many years it went before it failed to charge and I had my first squib in 50 years of reloading, but it's more than 5 years. So, I'm back to weighing every drop, but the PACT makes it easy. I didn't get into reloading to be fast anyway; I got into it to be accurate.

[benedict1]

So, I figured I would only need to check the bigger drops every 6 to 8 rounds or so and I would be ok. I was wrong. I now use my PACT dispenser/scale to load everything.

Wrong about what? What charge weights? What weather conditions--cold and dry with lots of static? Variation high or low? How much variation?

I neglected to mention in my post above that I use a modified RCBS baffle-bent slightly to fit the poweder measure.

Did you ever get into a situation where you weren't flaring a case much and the auto disk did not complete its complete cycle? If so, you can leave powder hung up on the lip of the measure next to the drop hole.

[swmike]

When I have to load a flake powder like Unique I use a different technique with my press. When the handle is down, I give it an extra "nudge" to shake the entire press. When it is up and I have seated the primer, I do the same. It keeps the powder in the hopper settling so I don't get bridging. As long as one does this the same, loads will drop uniformly.

My bullet seating station is where I can shine a lite on the mouth of the powder charged case. I watch for visual variations of powder level and check any that doesn't look right. By doing this, squib loads due to no powder (or real low powder) are minimized. If you are using a press that has a provision for Charge Monitoring, by all means use it.