Soooo... why don't tumblers clean the INSIDES of cases?

[FOGeologist]

I have just fire-annealed, lubed, resized, trimmed, chamfered and deburred 450~ish cases from several manufacturers.  In tumbling these shells, I noticed the insides of cases don't become polished.

How come the corn-cob media, which 100% fils the inside of every case, knows not to vibrate and clean those cases? Do you really think that the tumbler (an RCBS unit, so it should be good) hasn't got the power to vibrate the inside of the cases? 

[DustBuster]

I have noticed this too before... maybe it is because the media works in concert with the brass and in between the mass of the brass tumbling around  to polish and abrade the outside, but inside the individual cases there is only the media itself and it’s mass is little providing not much friction force.

FrictionForce = Normal Force (i.e. Mass*g) * Coefficient of Friction.

The Coedficient Of friction is the same in both case(inside and outside of case) but the Normal Force is different.  Less inside the case.

That would be my guess but I only got an B- in Dynamics

 

[sketch]

I went from corn to walnut with the polish powder... ( dry system) to a wet Franklin rotary tumbler. Uses steel pins and soap. Makes all the difference 👍

Edited September 30, 2022 by sketch
Note the inside are never perfect.

[Cunuckgaucho]

For me I found wet tumbling not only did a better job but was overall a lot cleaner. Everything is trapped by the water and doesn't end up in the air or dusting the workshop.

Comparing notes with a friend in a different part of Canada and his water is 'harder' than mine which results in different cleaning recipe.

[sketch]

Put a bucket over your dry tumbler if it fits and reduce noise and dust. 

[bubbas4570]

8 hours ago, sketch said:

Put a bucket over your dry tumbler if it fits and reduce noise and dust. 

I do something along those lines, I just use a big aluminum light fixture reflector....👍

[bubbas4570]

And I also used to do the ultrasonic cleaning system for my brass.  THAT cleans them very well also, I am assuming as well as wet tumbling, but the volume just wasn't up to what I needed to get things done.

[dpete]

14 hours ago, sketch said:

I went from corn to walnut with the polish powder... ( dry system) to a wet Franklin rotary tumbler. Uses steel pins and soap. Makes all the difference 👍

Wet tumbler with stainless steel pins, Dawn dish soap, and Citric Acid powder(the working ingredient of brass polish) and they come out sparling inside and out.  Gotta deprime rifle cases first though.  After they are completely done being processed a 30 minute dry vibro tumble in Walnut lizard bedding with a dab of nu-finish car polish and they gleam.  Ask @98Z5V, @Sisco how I know.

Edited September 30, 2022 by dpete
added details

[Sisco]

1 hour ago, dpete said:

Wet tumbler with stainless steel pins, Dawn dish soap, and Citric Acid powder(the working ingredient of brass polish) and they come out sparling inside and out.  Gotta deprime rifle cases first though.  After they are completely done being processed a 30 minute dry vibro tumble in Walnut lizard bedding with a dab of nu-finish car polish and they gleam.  Ask @98Z5V, @Sisco how I know.

Your cases are immaculate.

[FOGeologist]

21 hours ago, DustBuster said:

I have noticed this too before... maybe it is because the media works in concert with the brass and in between the mass of the brass tumbling around  to polish and abrade the outside, but inside the individual cases there is only the media itself and it’s mass is little providing not much friction force.

FrictionForce = Normal Force (i.e. Mass*g) * Coefficient of Friction.

The Coedficient Of friction is the same in both case(inside and outside of case) but the Normal Force is different.  Less inside the case.

That would be my guess but I only got an B- in Dynamics

 

I haven't read any other responses, but BOY, does that sound correct!

[DustBuster]

It could be.  Maybe it is an oversimplified look at it... regardless, sounds like these other guys know how to solve the dirty inside case problem.  I can’t shoot good enough to warrant that kind of case care for myself... I’m setup with walnut and corn dry tumbling with an extra sprinkling of some Bon Ami powder for some more abrasiveness.  But who knows maybe if I did clean the inside by wet tumbling the charges would be more consistent upon ignition. 

[dpete]

My main reason to go to wet tumbling was to get away from the lead tainted dusty mess.  You don't realize how bad it is until you see the water go into the tumbler clear, and come out black.  A good lung full or two of that toxic dust every time you tumble cases can build up over time.

[FOGeologist]

2 hours ago, dpete said:

My main reason to go to wet tumbling was to get away from the lead tainted dusty mess.  You don't realize how bad it is until you see the water go into the tumbler clear, and come out black.  A good lung full or two of that toxic dust every time you tumble cases can build up over time.

Kind of a point, here. There is a LOT of the lead from "non-completely jacketed bullets" of the cheaper FMJ-variety, invariably that vaporized lead is left on the insides of cases. Which means you get to deal with its vapor every time you unass the cleaned brass from the tumbler.

[Lane]

Primers contain lead, and lead free primers are still not very common.

Based on how ignition happens inside the cartridge, I'd assume a non-trivial amount of that lead stays inside the cartridge as part of the dark residue left behind. 

 

[Steve crawford]

I use a Thumbler Tumbler for wet cleaning.  I have both ceramic and stainless steel media.  I prefer s.s. over the ceramic.  Just be sure that you clean the media after each use.  I didn't clear after some Black Powder cases and the next load came out looking like Black Chrome.  Very shinny gloss black.  Washed the pins real good and ran the cases again,  They came out looking new.  Wet Stainless pins ( distilled water (water in my area has a lot of minerals in it so the distilled water ) 1 tablespoon of Dawn Dish Soap and 1 or 2 table spoons of Lime-Shine will look like new brass in 2 to 3 hours of tumbling.  If they are really dirty it may take longer.  Rinse the cases well and spread on a wire screen drying rack and sun dry for several hours to get all moisture from inside of cases.  Wet tumbling with Stainless Steel is the only I have found to clean inside the case, primer pocket, and flash hole.  just watch for pins in the flash hole after cleaning. After drying I resize and vibrate in walnut media and Lyman Turbo Bright for a couple of hours to remove the sizeing lube and final polish the cases before I finish reloading them.  It took me many years to get to this point ,  I have rounds I have loaded that are several years old and they still look like new.

Edited October 11, 2022 by Steve crawford

[Czgunner]

I wet tumble with a Thumler, and haven't had much issue getting the interior of the cases pretty clean.