Auto disk

[Reloader]

My Autodisk powder measure was throwing loads that were 4.3 to 4.4 grains of Titegroup. . Recently it started throwing 4.4 tot 4.5 grains.
This is with a new can of powder.
I swapped out the disk for another and now it is throwing 4.2 to 4.3 grains.
Is it normal for a disk to wear to the point it increases the load?
Can powder density change enough from lot to lot to explain this difference?
Can there be that much variation in two of the same sized disks?

[Fyodor]

I've never seen a disk that was worn to throw larger volumes. But I also experienced quite considerable differences between two batches of the same powder.

[Ranch Dog]

Is it normal for a disk to wear to the point it increases the load?

I really cannot see any wear in a disk happening; powder vs. the material the disks are made of.

Can powder density change enough from lot to lot to explain this difference?

Yes, most definitely it can. According to Lee and a few other sources I've found the weight of a given volume of powder, lot to lot, can vary from 15% ~ 16%. I just experienced this difference with Lil' Gun. The new lot was 13% heavier for the given volume. When I crack open a new jug of powder, I do calculate the VMD of the powder and write it on the jug. I've always wished that I had recorded those VMDs over the years, they were tossed with the empty containers, as it would be interesting to see the differences over several containers vs. just one.

Can there be that much variation in two of the same sized disks?

I don't think so but I've come to believe that there are day to day variations in VMD (or more specifically density). I do see slight differences, like you are seeing, on different days. I've come to believe that it is caused by slight variations in humidity and the powders response to it. There is no doubt that smokeless powder absorbs water, that is how it is made inert, but if dried it supposedly it is back in business. I've never tried it but if this is the case it's density would change with changes in humidity.

Static also affects the flow of powder across the things that it contacts and we tend to think that we only address this when the components of a powder measure system are new. I'm pretty sure that static can build for a number of reasons, might even be that humidity thing, the drying of a room. If the two disks you used were prepared at the same time with no use in between, any difference might be a slight difference in the cavity but I really don't see this especially with the small cavities. It seems to me that static would affect the smaller cavities more because there is less a gap across the column of powder.

I've become not too concerned about a slight day to day change of the charge being dropped but I am concerned when there is a trend, up or down, of the charge being dropped. That would be an indication that something is going on and needs to be investigated.

Early this week, I started loading for my Rossi 92 chambered in 44 Mag. I wasn't using the Auto Disk, instead I was using the Perfect Powder Measure to drop the charge but it is influenced by these same factors. I started to experiencing continuous light charges shortly after I started, I'm dropping a max load from the PPM into pan of the Safety Scale. It was enough of a continuously decreasing change that I stopped what I was doing and took a look. I dumped the powder out and immediately saw a possible problem.

T303_holding_powder.jpg

I set the baffle aside, refilled the PPM, and continued without further issue. I wish I had set the baffle in a place that was picture friendly as it was coated with powder. This morning it had released most of the powder but there was still some sticking like glue. This baffle has been in use for some time without issue but on that day, something caused the static as the powder started drifting across it. My reloading room is a very controlled environment but we do get some wild swings in humidity this time of year with little temperature change. Central heat & air conditioning only responds to temperature so it really hasn't been running but I'm sure had I been able to record humidity, I would have seen a significant change in the room. When I looked at the hydrometer it was a 40% and I know at one point it was slightly above 55% so some drying had occurred in the room.

This post caused me to remember the baffle so I went out, took the picture, and washed it with Dawn Ultra & very hot water. I've often thought about storing these various metering systems full of dry graphite and then dumping them immediately before use. I wonder if that would control these slight variations? What is graphites response to humidity?

[Maximumbob54]

This is going to sound silly.

Dryer sheets.

No kidding. I read about this tip a few years back and now swear by it. Whatever the stuff is on the sheets negates static. I used to empty the powder by dumping it and everything plastic had bits of powder stuff everywhere still. I would brush at it and it would just move around until it finally would brush free. Now I have a dry sheet that I use to wipe everything down and stuff into the reservoir and swish around with a dowel rod. Poof, static gone.

Also, for what it's worth, Snuggle is still labeled as being made in the USA and is the only one I've found that says this.

[62chevy]

This is going to sound silly.

Dryer sheets.

No kidding. I read about this tip a few years back and now swear by it. Whatever the stuff is on the sheets negates static. I used to empty the powder by dumping it and everything plastic had bits of powder stuff everywhere still. I would brush at it and it would just move around until it finally would brush free. Now I have a dry sheet that I use to wipe everything down and stuff into the reservoir and swish around with a dowel rod. Poof, static gone.

Also, for what it's worth, Snuggle is still labeled as being made in the USA and is the only one I've found that says this.

Never thought of leaving the dryer sheet in the reservoir. What I have found, this site clued me in, is wash in dish soap do not rinse and let dry. this has worked mostly for me. I'll have to get some snuggles.

[Fyodor]

I've tried dryer sheets, and all that happened was that unpleasent scent in my reloading room. The static was a little bit less, but still too much to take the stink of these dryer sheets.

The plastic parts in contact with powder eventually will get an anti static covering by the graphite that's on the powder granules. That's good enough for me. I tossed the dryer sheets.

[Ranch Dog]

I've tried the dryer sheets but prefer the hot water and soap.

Back to the OP's problem, any other reasons?

[Steve]

The next powder measure I get I plan on washing it with soapy water, when it dries do the dryer sheet wipe. Then I'm going drowned it in a coffee can of powder for a few days.

[Fyodor]

Back to the OP's problem, any other reasons?

I don't think so.

Powder should not cause any wear on the disks, and on my measures the disks with the same holes throw the same amount of powder.

The only thing that creates quite noticable changes is another can of powder.

[Ranch Dog]

Is it normal for a disk to wear to the point it increases the load?

I really cannot see any wear in a disk happening; powder vs. the material the disks are made of.

Can powder density change enough from lot to lot to explain this difference?

Yes, most definitely it can. According to Lee and a few other sources I've found the weight of a given volume of powder, lot to lot, can vary from 15% ~ 16%. I just experienced this difference with Lil' Gun. The new lot was 13% heavier for the given volume. When I crack open a new jug of powder, I do calculate the VMD of the powder and write it on the jug. I've always wished that I had recorded those VMDs over the years, they were tossed with the empty containers, as it would be interesting to see the differences over several containers vs. just one.

Can there be that much variation in two of the same sized disks?

I don't think so but I've come to believe that there are day to day variations in VMD (or more specifically density). I do see slight differences, like you are seeing, on different days. I've come to believe that it is caused by slight variations in humidity and the powders response to it. There is no doubt that smokeless powder absorbs water, that is how it is made inert, but if dried it supposedly it is back in business. I've never tried it but if this is the case it's density would change with changes in humidity.

Static also affects the flow of powder across the things that it contacts and we tend to think that we only address this when the components of a powder measure system are new. I'm pretty sure that static can build for a number of reasons, might even be that humidity thing, the drying of a room. If the two disks you used were prepared at the same time with no use in between, any difference might be a slight difference in the cavity but I really don't see this especially with the small cavities. It seems to me that static would affect the smaller cavities more because there is less a gap across the column of powder.

I've become not too concerned about a slight day to day change of the charge being dropped but I am concerned when there is a trend, up or down, of the charge being dropped. That would be an indication that something is going on and needs to be investigated.

Early this week, I started loading for my Rossi 92 chambered in 44 Mag. I wasn't using the Auto Disk, instead I was using the Perfect Powder Measure to drop the charge but it is influenced by these same factors. I started to experiencing continuous light charges shortly after I started, I'm dropping a max load from the PPM into pan of the Safety Scale. It was enough of a continuously decreasing change that I stopped what I was doing and took a look. I dumped the powder out and immediately saw a possible problem.


I set the baffle aside, refilled the PPM, and continued without further issue. I wish I had set the baffle in a place that was picture friendly as it was coated with powder. This morning it had released most of the powder but there was still some sticking like glue. This baffle has been in use for some time without issue but on that day, something caused the static as the powder started drifting across it. My reloading room is a very controlled environment but we do get some wild swings in humidity this time of year with little temperature change. Central heat & air conditioning only responds to temperature so it really hasn't been running but I'm sure had I been able to record humidity, I would have seen a significant change in the room. When I looked at the hydrometer it was a 40% and I know at one point it was slightly above 55% so some drying had occurred in the room.

This post caused me to remember the baffle so I went out, took the picture, and washed it with Dawn Ultra & very hot water. I've often thought about storing these various metering systems full of dry graphite and then dumping them immediately before use. I wonder if that would control these slight variations? What is graphites response to humidity?

Getting caught up on some stuff around here and wanted to report back on the "Dawn Ultra" wash and results. Here is the baffle after the bath and after use...

T303_holding_powder_02.jpg