My Fix for Leaking Auto Drum

Auto Disk, Pro Auto Disk, and Auto Drum Powder Measures along with their associated charge bar, disks, and drums.

My Fix for Leaking Auto Drum

Postby sparkyv » 26 Aug 2020 18

I never could get my two Auto Drums to stop leaking with small grain spherical powders. I tried to make the Lees work because I use them on my Lee turret and enjoy the auto activation feature. I read up on other options and decided upon the RCBS Uniflow with an adapter to sit on the Lee powder through expander die, but with manual powder activation. I am impressed with the repeatability of the measure and NO LEAKS!

There is a downside to this setup; the measure is pretty heavy compared to the polymer Lee measures, so the added weight puts more strain on the indexing system, so I have to index more slowly and deliberately so as not to bind up the system or overshoot the next die position. Not a deal-killer at all, I just have to adjust my turret indexing method a bit.

And the icing on the cake? RCBS is running a rebate!
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Re: My Fix for Leaking Auto Drum

Postby GasGuzzler » 27 Aug 2020 06

I have a UniFlow and adapter buy I only use it on my single stage because of the weight. My AutoDrum is fine after using it for a while.
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Re: My Fix for Leaking Auto Drum

Postby horseman » 28 Aug 2020 10

Sparky, I've had my share of "issues" with my auto drum measure and my final solution has been to lap the insides with lapping compound. I'm not advocating this to anybody but it has pretty much eliminated all the leaking problems I had. I actually just lapped it again yesterday (might not have been enough the first time) as it was still losing a small amount of Accurate 7 which is a fine grained powder, after the first go round. It was leaking out the back side, guessing through the gear portion. Cleaned with brake cleaner then washed with soap and let dry. Tried it again in the afternoon and all leaking had stopped. Powder (AA7) was within a tenth of a grain after several throws. Probably should run a full hopper through it. I did coat the drum with graphite prior to the start. Will run some more before I use it to load with though. Just something to consider.
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