the effects of wet tumbling

[car-ram-rod]

so after about 2 full months of high volume shooting I've come to the conclusion that SS wet tumbling has given me some bad results in precision reloading....

since switching to wet tumbling my run out has increased in a few calibers and it looks like my neck tension has changed also. which in turn has taken a proven load of 8fps SD to 16fps SD.

i really like the appearance the SS wet tumbling gives me. BUT not at a performance sacrifice.

I'm going to take a few sets to see if i can fix the issue before ditching wet tumbling. switching to mandrels, pulling all the expander balls and using a dry lube for the necks.

just thought this maybe some would like to know before investing.

[ArizonaGunOwners.com]

[coelacanth]

I've often wondered what the microscopic effects were of tumbling steel pins in brass cartridge cases.      There have to be some, just maybe not visible to the naked eye and not readily measurable.  Shot peening a metal surface changes the metallurgical properties of the underlying metal to some degree and I would think that brass would be no different in that regard.   I understand that what happens in a tumbler is not the same thing that happens in a high pressure blast cabinet but the brass may be in there for a couple of hours vs a piece of metal that spends only a minute or so in the cabinet. 

Considering that brass is hardened slightly by working it at cold temperatures there may be some slight dimensional differences being wrought inside the tumbler and then hardened in place over the tumbling cycle.      Not enough of a metallurgist to say for sure but the steel pins are certainly harder and tougher than the brass they are being tumbled against. 

I would think even slight dimensional differences in the primer pockets and the flash holes could affect your ignition enough to cause problems at the level of precision you are trying for. 

Its probably just an engineering problem that can be overcome by tweaking a few things but its also the kind of thing with so damned many variables it could take you a year to sort it all out.   

[car-ram-rod]

and i anneal the necks and shoulders

[coelacanth]

After tumbling - right? 

[car-ram-rod]

yup

[RSM]

I probably don't do near the volume of shooting you do but so far I haven't noticed any decrease in accuracy. My .223 is a big majority of what I reload. I have about 2000 pieces of that. How many pieces do you have and how many times have they been cleaned? I probably haven't been thru mine enough times to notice anything yet.

[car-ram-rod]

a lot and a lot..... haha. i don't hold back at all when i shoot and the kids shoot a lot against each other

[RSM]

Does brass ever get to the point it's not usable even if it looks good and isn't cracked or damaged?

[car-ram-rod]

not that i know of. i anneal all rifle brass after its been cleaned also. again this is minor for most but huge for precision work

[RSM]

Annealing is something I've been looking at. At some point in time I'll buy an annealing machine.

[Thernlund]

Considering that brass is hardened slightly by working it at cold temperatures there may be some slight dimensional differences being wrought inside the tumbler and then hardened in place over the tumbling cycle.      Not enough of a metallurgist to say for sure but the steel pins are certainly harder and tougher than the brass they are being tumbled against. 

Work hardening is a major debate point in the wet tumbling community.


-T.

[steve2md]

You should get less runout and a smaller sd when you start dry lubing the necks. It's the built up carbon that gets left behind in vibratory tumbling that acts as that lube normally

[car-ram-rod]

Well I was also getting so much drag that I went to using a q tip with imperial die wax to lube the neck. But that didn't help

[FiveInADime]

Well I was also getting so much drag that I went to using a q tip with imperial die wax to lube the neck. But that didn't help

My friend and former neighbor, who is a short-ranger benchrest shooter, wet tumbles pistol brass but he uses a vibratory tumbler for benchrest. It leaves the carbon on the inside alone which for lubrication or whatever reason is considered a boon to consistency in benchrest circles.

I wet tumble with no media. Just Lemi-Shine and a few drops of drawn. It leaves some fouling in the case, the primer pockets don't get very clean, and the outside is still very shiny. I do 100 .223 cases for about 45 minutes or 50-70 larger rifle cases. I only shoot low-volume (bolt actions).

The only real benefit to SS pins is that they clean the primer pockets. The wet tumble will get the cases really shiny without the pins.

Sent from my SM-G920V using Tapatalk

[FiveInADime]

Well I was also getting so much drag that I went to using a q tip with imperial die wax to lube the neck. But that didn't help

Also, get some graphite powder or mica instead of using the imperial for the necks. I bet you'll get your consistency back.

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[RSM]

I might have try a wet tumble without the pins. Having clean primer pockets is really nice. It's one step I don't have to mess with.

[car-ram-rod]

If I can't get the consistency back I may do that. Wet tumble pistol and dry rifle

[coelacanth]

If you are chamfering for VLD bullets the edge of the case neck is thinner than a normal chamfer and they may be getting dinged up from tumbling against each other.  That link I sent you mentions varying the amount of tumbling media vs cases to help alleviate that problem.  I think the guy only tumbles maybe 50-75 cases at a time and then only for about 25 minutes with a full load of pins.  Apparently that and the level of liquid in the tumbler are fairly critical to getting a good result.   

[ArizonaGunOwners.com]