Wet tumbling emrittles brass?

[blue32]

To offer a comparison, my FL sized 223 will generally achieve neck cracks at 20% of the lot on the 9th reload. I typically toss the lot at that point. I dry tumble and the rounds are fired in an AR. I've noticed LC, Federal, Aguila, Rem and PPU to have fairly consistent failure rates.

[onelight]

Many people wet tumble brass with pins with no excessive splitting after many cleanings some with huge timber's with many more pounds of brass and pins that would greatly accelerate any work hardening from peening.
To my uneducated brain it would not be the process of rolling a few pounds of bass and pins in a small container dampened with fluid , if so this would be a common problem to many of us.
It will be interesting to see if a solution is found.

[modified5]

Interesting thread. I only dry tumble with a small amount of Cabela's polishing compound in it. A whole bunch of years ago I bought 1000 once fired military brass to feed my ground squirrel addiction. We used to go out almost every weekend and shoot between 500-1000 rounds of various .22 rounds. I would spend the next week reloading and buying more 22lr for the next weekend. All the .223 got full length resized because it was used in multiple guns. I never annealed the brass. My failure rate was really low. I did have one piece of lc68 that finally had a complete head separation after who knows how many reloads. Took a cleaning rod to get the body out.
I can't imagine wet tumbling having that big an impact, but I have been wrong before.

[fatelk]

I’m not entirely convinced that it’s the tumbling; I just don’t know what else it could be. In my mind, the nearly 100% failure rate in widely mixed brass rules out an inherent brass problem.

I had a batch of .222 ammo that all cracked the same way once, long before I ever wet tumbled. It had sat for about 20 years. I also had some 30-06 rounds where a lot of them cracked too. They had also sat for 20+ years. I never annealed back then either. I made the assumption that this happened due to used, unannealed brass sitting loaded for years and years. This .223 ammo sat for just a year.

[leadhead 500]

I can promise you that it’s not the wet tumbling causing the brass to split. I wet tumble everything I load for now days from 223 to 50 Bmg in a 15# rotary tumbler using stainless Steel pins, Lemi shine, a small squirt of dawn and hot water. I run them for around 30 minutes and take them out and dry them. Over the years of reloading thousand and thousands of shells and most of the case cleaning was done with a vibratory tumbler and media, I have no more neck splits using the rotary tumbler compared to the vibratory tumbler. I have run into seeing many thousands of Lake City brass being harder than a lot of commercial brass

[bigboredad]

I have a few friends that wet tumble and at first they used the lemishine steel pins and all the recommended recipe. After about a year doing it they quit using everything except dawn dish detergent.
They are all brass hounds and pick up everything they find and they tell me the dawn gets them looking brand new even primer pockets.
They also use a dehydrated to dry their brass

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[salpal48]

I have beens saying This for several Years now. Pin tumbling will ruin Brass. Like most Loaded I use the same batch of brass over and over again. After Firing i would tumble clean with Pins , water and citric acid. after a wile I noticed the brass would Have an Orange Peal Effect On them. Micro dent that You would Feel @ the touch. Upon firing the micro dents brass would Blow out and leave the Brass somewhat " Frosted".. then i would dump them.. ater that went back to media . Never happened again

[Seeker]

If you used too much lemshine your brass would be pink also.

[dbosman]

Having wet cleaned a ton of brass, literally a ton, I have opinions on wet tumbling. I stop at two hours. I advise the use of a timer.
If you look at the case mouths, after cleaning, you can see serrations from the case edges hitting case edges. If you look at your wash water in bright light, you'll see flecks of brass or light glinting off the flecks. Dirt is being removed, as is the patina, but also enough brass to see those flecks. I never thought of trying to mark and weigh cases, but some brass is coming off.

Could the pounding that is removing some brass be enough to harden the cases?

[Four-Sixty]

I wonder if tumbling in pins introduces galvanic corrosion. After all, we have dissimilar metals in an acidic solution.

We should track the results as JimB suggests.

[onelight]

I wonder if tumbling in pins introduces galvanic corrosion. After all, we have dissimilar metals in an acidic solution.

We should track the results as JimB suggests.

That is an interesting thought . Would the pins be brass plated if this was happening ?

[Fireball 57]

Merry Christmas, Everyone! My range pickups of brass gets a dry tumble of about three hours in cob media ie: not news media. This removes surface sand and some corrosion. Separating and sorting the cases, eliminates defects. Selected cases are deprimed,sized, deburred and chamfered,ready for a boiling bath on the kitchen stove,of four minutes, then a cool water rinse and in the oven to dry at 260 degrees for 15 minutes, air cool, ready to load. All without steel pins. With a couple tablespoons of Lemishine, a dash of Phosphate-free dish soap AND a splash of liquid cheap car wash, my Dillon purrs like a kitten. NO split cases. No harm or foul. Have a great day! Fireball 57

[10mmShooter]

Industrial shot peening is a process used to remove residual stresses in metals. Just isolating the tumbling of brass with the ss pins. This is a net removal of stress in the brass. If anything it would make the brass softer. But in general its assumed the impact and action of our wet tumblers is no where near the impact and energy involved in "real" industrial shot peening. Hence no effect on the brass structure. Easy to test this hypothesis take a few pieces of factory new brass cartridges, as the control, then take a like sample and wet ss tumble the crap out of them for some unrealistic number of hours in the tumbler. Then send the two samples off to a materials lab and have the brass tested for composition and tensile strength and hardness. Only way to know for sure. I assume RCBS, Lyman may have already had this done this ?? who knows call and find out.

[igolfat8]

I agree with 10mmShooter. It’s common to stress relieve weldments using a needle gun to impact the fresh weld with thousands of impacts. So there is a tiny correlation between the two processes but as mentioned the SS pins don’t make an impact that is nearly as forceful as a pneumatic powered needle gun but one could conclude that it would tend to soften as opposed to harden the brass.

I wet tumble and shoot mostly 9mm open brass, which is a high pressure round. I shoot at least 15K rounds per year so 8 process a lot of brass. Rarely do I find split brass cases. However, I do find that nickel cases split with predictable regularity. I only get one or two reloads on nickel cases before they split. I’ve read where the nickel plating makes these cases harder so maybe there is some correlation to hardness and cracking?

[fatelk]

Steel and brass are two very different metals, so I'm not sure what that tells us.

I will say that I've tumbled a lot of straight wall cases: .30 Carbine, .44 Magnum, 9mm, .40 S&W, .45 Colt, etc.. Some of them, especially .45 Colt and .30 Carbine, have been tumbled more than once. I haven't noticed any cracking in them. So far, the only unusual cracking has been in .223 and .270, but those were also the only ones that sat loaded for any length of time. The 100% failure rate of the .223 ammo is the mystery I can't figure out. It's clearly work and/or age hardening/embrittlement, since annealing helps. Why exactly? I don't know. I'm not completely convinced one way or another about wet tumbling.

I'll still use my tumbler. I just did an experiment. I tumbled some brass for 45 minutes, with just a light sprinkle of Lemishine and a squirt of Dawn. It came out fine. One piece of range brass that was pretty tarnished wasn't quite as shiny as I'd like, and the primer pockets weren't quite spotless, but in reality it's all fine. I'm convinced that I was tumbling far longer than necessary. Does it hurt? I don't know, but from now on I'll tumble less and anneal anything that's likely to sit around very long. That's my plan.

[Traffer]

The zinc in brass can be bled out of it after some time in water, but what you want to avoid is salt LOL.I say that because I tried a YouTube recipe of water vinigar,and salt once ,and I ended up with greenish yellow water,and pink brass.LOL.

Yup I did something similar but not with salt. I think I used some other kind of caustic stuff in the tumbler...Got pink brass...brittle as hell.