Trail Boss, Lee Auto Disk and Small Charges

M

Mike Irwin

Staff
Anyone have issues with the Lee Pro Auto Disk not dropping small charges of Trail Boss?

I'm loading for .32-20 for my S&W and Colt revolvers -- 115-gr. lead bullet, 2.2/2.3 grains of TB (bottom end load).

In the first 12 rounds I had TWO dry cases that lodged bullets in the bore. Fortunately they weren't in tightly and I could, with some effort, push them out with a rod.

In talking with a friend who also uses TB, the only thing we can figure is that it's the donut-shaped powder bridging across the small hole in the disk and not dropping.

In over 30 years of reloading I had only ever had one other dry case.

I'm thinking I'm just going to drop TB for .32-20 and go with either Universal or 231.

I'd consider Unique, but given its reputation, I'd be afraid of it bridging, too.

Any thoughts?
 
I think it's the lightness and fluffiness of the kernels. I can't help noticing the way it sticks to your fingers and the lip of the container. I love the idea behind it but I don't think it's well suited to high volume reloading. I do everything by hand, one step at a time.
 
It's the first problem like this I've heard of, but can imagine it happening. I wonder if you might overcome it by vibrating the powder hopper a little. I know a couple of people have put a fish tank aerator pumps on their powder hoppers with heavy rubber bands and rigged to a button they press to vibrate it briefly when the metering cavity was open to it. That can be rigged to happen automatically with a timing relay, but it's a bother.
 
I've not had similar problems when using TB for .44 Special. Larger charge, larger didk.

I thought about some sort of vibration, but it would have to be self contained as the measure spins with the turret on my Lee Classic.

I may try tapping the measure body with a screwdriver handle if I stick with TB.
 
Similar bridging situation trying to dispense TB into .25-20 cases with a RCBS measure. Resorted to using a larger dispenser funnel with the RCBS that was too large for the case mouth and then dumping into a funnel and then tapping the TB into the case. Slow going but it worked.
 
Maybe a long drop tube would solve it in that case. But with the turret press, maybe the whole press could be vibrated from the frame rather than just the powder hopper.
 
"Maybe a long drop tube would solve it in that case."

The Lee Auto Disk mounts directly to the top of the belling die, and is activated by the case being run up into the die. It would require a LOT design and machining to fit a double-sleeved drop tube that would activate the measure.

Also, I don't think that the powder is bridging at the case mouth itself -- it would appear to be doing so in the measure, where a drop tube wouldn't do anything.

"But with the turret press, maybe the whole press could be vibrated from the frame rather than just the powder hopper."

I'm pretty sure that in order to provide enough vibration to my cast iron press I'd have my entire loading bench jumping around.

I've thought about setting up my Belding and Mull measure and charging the cases separately, but damn that's a lot of extra work.

I think the easiest solution is going to be switching powders.

I really like Universal in .45 Colt, so I may try it in .32-20.

I may also see if I can find some loading information for AA 7, since I have a fair amount of that.

And... no. No loading data for AA 7 and .32-20.
 
Right. The case I was referring to for the drop tube was CB's RCBS measure. The turret press is a different matter. The vibration still might work, though. If you put the aerator pump on top of the bench, you can probably feel it across the bench surface. You can certainly hear it if you place your ear on the bench. By the time I did something like that, though, my wife would start laughing and want to know if I thought a train was coming.

I would probably lean my demagnetizer up against an iron press frame. That would buzz it. I expect a small battery-operated motor with an eccentric weight on the end could be rigged to the hopper with a microswitch on the measure actuator to run it. But this is all getting to be an awful lot of bother compared to just changing powders.

I realize I've never tried to get Trail Boss into anything smaller than a .38 on a progressive press. Maybe you've found the lower limit is around .264 or so.
 
You might consider getting the new Lee Auto Drum pm. It is a definite upgrade from the pro auto disk. I don't use Trail Boss and I have never tried throwing such a small charge of any powder with it, so I can't say it will definitely work. But, it wouldn't surprise me if it worked much better in this instance. If it doesn't, you will like it for your other loading endeavors and it is relatively cheap. Just a thought.
 
A round hole in a disk would be better suited than the squint eye you would get with an Adjustable Charge Bar. You would have to settle for approximating the charge you had in mind.
 
I am using the disk, not the charge bar.

I was thinking about a drum measure, but I already have a Uniflow and the Belding and Mull...
 
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