Off use of a tumbler

[Roamin_Wade]

I don’t reload...yet, but I have some whole, unspent 30-06 shells that have some superficial surface corrosion on them. I’d post a pic but I still can’t figure out how to post pics with my phone. Can I put whole loaded bullets into a tumbler to polish the corrosion off of them? Also, how much time does it take to tumble-polish a load of shells? Thanks for your input...

[stillquietvoice]

I just posted my first pics. Downloaded google pictures and learned to crop photo. It reduces file size of pic then save smaller image. Right below post text screen is manage attachment button upload from file and it will submit with your post.

[wv109323]

No I would not tumble loaded ammo. The burning rate of powder is somewhat regulated by its physical size of the granules. By tumbling the ammo the powder may become finer and affect its burning rate and thus increase the pressure when fired.
Fire the ammo and then clean the cases.

[USSR]

As wv109323 said, you don't want to tumble loaded ammo. If the surface corrosion is bad enough, wipe them with some "0000" steel wool until they look good enough to shoot.

Don

[Sure Shot Mc Gee]

Nope! not a good idea tumbling live ammo.
A little Brasso polish sold everywhere will also remove light corrosion.

[Roamin_Wade]

Hmm, I wouldn’t have thought that the powder inside the shell could break down in such a way that it would cause a dangerous pressure issue. Is it because of the high frequency vibrations that some tumblers have or just the fact that they turn and roll so long that does it? Also, if it is the frequency vibration can it be turned off so I can do this or do all tumblers have vibration that can’t be turned off? Would the media do the job alone?

[OKElkHunter]

Originally Posted by Sure Shot Mc Gee

Nope! not a good idea tumbling live ammo.

A little Brasso polish sold everywhere will also remove light corrosion.

Never use brasso or other polishes that contain ammonia on ammo components. Ammonia breaks down the brass and weakens it. It will cause those corroded spots to become thin and the cases could rupture when firing.
There are non-ammonia based cleaners available but the steel wool mentioned would work fine as long as the corrosion isn’t too bad. If the corrosion is excessive, I’d get new ammo and discard the corroded stuff.


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[mikld]

The "tumble, don't tumble live ammo" controversy has been going on since I started visiting reloading forums in 2008, prolly longer, but that's when I started seeing it. I have seen no definitive proof from either side, just 99.9% speculation. I've read "tests" for "pro tumbling" and I've read posts citing a reloading manual. But I have tumbled some live ammo (200 old tarnished military surplus 30-06) with zero ill effects...

For a brand new reloader; don't get too involved with tumbling, it's 99% cosmetic. K.I.S.S. I started tumbling 12 years after I started reloading (I just wiped each case with a solvent dampened rag as I inspected it. no ruined dies, no scratched chambers). I started with a Harbor Freight rock tumbler and some walnut litter from Petsmart (dark). Works quite well. I now have a larger rotary and a wobbler, both work well with corn cob blast media...

[Unclenick]

Originally Posted by Roaman Wade

Hmm, I wouldn’t have thought that the powder inside the shell could break down in such a way that it would cause a dangerous pressure issue.

It's not. Keep in mind that manufacturers tumble canister grade powder to blend it with faster or slower lots of the same type powder to control lot burn rate variation. Also, keep in mind cartidges get vibrated in transportation, some of that being pretty vigorous with military transport, where it is subject to all manner of shaking, from trucks to air transport to parachute drops. It has to be able tolerate a good bit of this. actual testing shows no measurable effect. Read the whole thread at THR to get some sense of how the argument swings back and forth, but at this point I have to say I think most of the concern stems from manufacturer's concerns about liability rather than actual science. Still, in theory, tumbling can't go on forever before vibration finally does start to wear through the deterrent coating, speeding up the burn rate of the powder. But for a reasonable amount of time, it shouldn't be an issue.

My advice to you is to mix a 10% solution of citric acid in water and dab it onto the corroded places with a Q-tip to remove verdigris and white oxide blooming you see. Just keep any liquid the heck away from the primer pocket or it will wick in with unpredictable results for ignition. Ignore black oxide. It's stable the same as an annealing stain is. Some pinkish copper-colored red copper oxide will be left behind from the spot treatment. Ignore that, too. Rinse the dabbed spots off with plain water on another Q-tip. You can wipe it off with a rag dampened with distilled water to prevent water spots. The citric acid, unlike the vinegar and sulfamic acid sometimes used in case cleaning, will leave the surface passive, so it won't tend to re-oxidize.

If you are determined to shine it up before shooting them, I would go ahead, but I would test the result, just to be sure, given the lively debate on the subject. You could pull a few bullets and take the charge down 10% on one, 8% on the next 6% on the next and so on, until you are back to full charge. Reseat the reduced loads and fire them as a low-to high series while watching for pressure signs.

I don't know the age of your cartridges nor what tumbling might to do powder that was starting to break down. But that bullet-pulling will also give you a chance to confirm the powder isn't sticky or acrid-smelling and to dump some on a piece of white paper to make sure there is no red dust left behind when you pour it back into the case. If it has any of those signs of breaking down, I would be pulling all the bullets and dumping the powder on the lawn.

[gwpercle]

I use a little 0000 steel wool to remove corrosion from loaded rounds , do it while watching TV . Don't tumble .
Gary

[RC20]

I think everyone has to read Unclenicks comments and do what they think is for them.

I did get a couple of boxes of HXP and as it was slightly tarnished/ corroded, it got tumbled and cleaned up.

It shoots as poorly as it ever did! (but no sticky bolt either)

[Unclenick]

Took me awhile to relocate this thread. Unfortunately, it is a victim of the great Photobucket marketing blunder and all the nice high magnification photos of the powder grains are gone, though the titles are not. The bottom line was he accrued 300 hours of tumbling of some rounds and they still worked normally and he could see no difference in the powders before and after. Again, a deteriorating powder may be another matter, but I don't have data for that.

Anyway, the warning never to tumble loaded rounds (if the powder is in good condition) has looked more and more like a wive's tale to me as time goes by. Still, I don't blame the powder companies for nay-saying the practice as there is no upside for them to saying you can do it. If they say it's OK, sooner or later some numbskull will tumble a case with a double-charge in it and then blame tumbling the powder for causing the problem, and by extention, the maker who OK'd doing it.

[LE-28]

On Thr they tumbled pistol loads for up to 40hr straight and checked for velocity changes afterwards and didn't see any.

I tumble all my pistol loads except hollow points because my rotary tumbler packs the hollow point full and they are a bugger to clean back out.

I don't tumble rifle loads with soft lead tips. I tried it and my rotary tumbler beat the snot out the tips, bent them and marred them all up.

A vibratory may not hurt the tips but I only recently bought my first vibratory tumbler from a Black Friday sale.

My rotary is still running strong after 35years (homemade) but I couldn't resist the deal on the vibratory.

I will have to try this to see if the vibratory will beat them up or they will to heavy to tumble and just lay on bottom.

I have some old beat up .308s that look like I found them in swamp.

I'll put them in tonight to see if they will even tumble.

[LE-28]

Well, I through 3 of them in the vibratory tumbler and they sank like the titanic and didn't move after that.

If I left them in there overnight it may shine them up a little but after about an hour I couldn't tell any difference from when I through them in. They just weigh too much to move around in there and get the full benefit that an empty case gets.

I wouldn't waste my time unless you have nothing else to do. It certainly won't hurt them if they are healthy to start with.
These .308s of mine are going to be torn down and dumped out. I've been dumping a lot of rifle cases lately, stuff that's 30+ years old that has been carried a lot during hunting.
Follow what the other members here said and polish them out by hand. I use Never Dull for that, it will work after all the green stuff is off of them.

[Sure Shot Mc Gee]

Never use brasso or other polishes that contain ammonia on ammo components. Ammonia breaks down the brass and weakens it. It will cause those corroded spots to become thin and the cases could rupture when firing.

Nonsense. As understood it's a one time cleaning of exterior surface corrosion. #0000 steel-wool is likely to scratch away more brass material overall than a light coat of Brasso.

[USSR]

Quote:
Never use brasso or other polishes that contain ammonia on ammo components. Ammonia breaks down the brass and weakens it. It will cause those corroded spots to become thin and the cases could rupture when firing.

Nonsense. As understood it's a one time cleaning of exterior surface corrosion. #0000 steel-wool is likely to scratch away more brass material overall than a light coat of Brasso.

The problem with ammonia is not that it will "scratch away more brass material", it is the metallurgical breaking down and weakening of brass. It is a known fact - ask any chemist.

Don

[mikld]

The problem with ammonia is not that it will "scratch away more brass material", it is the metallurgical breaking down and weakening of brass. It is a known fact - ask any chemist. USSR

This ^^. I did a bit of research the first time I read "use no ammonia" and USSR's info is correct, a chemical reaction can take place between the ammonia and brass. Weakening of the brass (I read a "side story" that once in WWI (?) a camp of soldiers stored some ammo next to the horse stalls and some of the ammo was ruined by the horse pee's ammonia content. Internet "story"? or true?)..

[Unclenick]

It's called "season cracking" because it was discovered by the British army in India that their case neck would start to split during the rainy season (monsoon season). They had the habit of storing ammunition supplies in their horse stables, and in the near 100% RH of the rainy season the manure and straw would start to compost and release the ammonia gas familiar to any home gardener who has ever turned a hot compost pile.

The Wikipedia has a write-up on it.

I can't recall if it was on our board or another, but someone did post about polishing ammunition with brasso and putting it in machinegun links to hang on the wall of his bedroom in high school. When he went to college the belts were stored in a trunk and he didn't see them again for 20 years. When he finally did open the trunk up he said there was powder spilled all over from cases that had opened up and corroded.

The problem with that kind of annecdotal tale is that I have no way to know if the Brasso did it or if the powder broke down and corroded the cases open from the inside. I've had that happen with odd surplus cartridges. I also know people who've used Brasso on cases and not identified any clear problem resulting from it, probably because the exposure was short. On the other hand, given that season cracking is a known thing, and given that there are ammonia-free brass polishes from Flitz and all the sellers of tumblers and even home recipes (make a slurry of mineral spirits and diatomaceous earth from the garden store) I can see no reason to use it.

[Roamin_Wade]

Thank you Unclenick! I think I land in your camp about all this. I collect bullets and I was thinking of doing this but a few days ago I got 3 full boxes of Federal 30-06 and 2 full boxes of 30 cal carbine that was lightly corroded but other than that looked fine. The boxes are new looking so I decided I'd try this and after hearing what you've said, I'm going to try it. Thanks again...

[hdwhit]

Roamin Wade asked:
Can I put whole loaded bullets into a tumbler to polish the corrosion off of them?

Be careful to distinguish "tarnish" of brass cases from "corrosion". Tarnish is simply the oxidation of the surface layer of copper in the case which produces a brown patina like an old penny. Corrosion involves an "attack" on the structure of the case involving both the copper and the zinc. It will generally be colorful, but may also manifest as a black spot that goes well below the surface of the brass.

That said, my answer is: Yes, provided what you are describing as "corrosion" is limited to the surface of the brass. If tumbling - or after tumbling - polishing with Brasso or a similar cleaner will not remove the defect, the round should be salvaged or discarded.

Tumbling brass will not cause it to ignite. It will not cause the powder to break into smaller pieces causing excessive pressure. It will not cause the bullet to loosen. Ammunition manufacturers tumble their rounds before packaging them to ensure they are cosmetically acceptable to the consumer. If tumbling ammunition was a "No-No", do you think the manufacturers would do it?

Of course not. The imagined - but yet to be demonstrated - effects of tumbling on loaded round are among the reloading community's equivalent of "urban myths".

They are illusion and should be ignored.

And as we have already seen, there is no greater urban myth within the reloading community than the one claiming Brasso and other cleaners that contain ammonia will damage brass. The reality is that exposure to small amounts of ammonia for short periods of time poses no threat for cartridge brass made after the late 1920's.

In the 19th Century, the British Army in India found their cartridge cases were developing cracks after being stored in the horse stables for months at a time. This is called "season cracking" because it only appeared after the ammunition had been stored in the stables for months. It was later determined that storing ammunition in the stables where horse urine produced copious amounts of ammonia was causing cracking in UNANNEALED cases (note the cases affected were NOT annealed). The cracks were caused when some of the copper in the brass reacted with the ammonia along the unrelieved stress cracks that were created when the case was formed.

Since the late 1920's, when the phenomenon of "season cracking" was scientifically explained, ALL cartridge cases have been annealed during manufacture. Thus, the circumstances necessary for "season cracking" to occur NO LONGER EXIST. Whether it is even possible for a case made in the last century to EVER be susceptible to "season cracking" is doubtful. But, it is clear the tiny amount of ammonia in cleaners like Brasso and the short time the brass is exposed to the ammonia (minutes instead of months) is in no way comparable to the conditions that lead to "season cracking".

Brasso is NOT "bad for brass". The circumstances that made ammonia a threat simply NO LONGER EXIST. Nevertheless, the "old wives' tales" seem to have a life of their own.

[USSR]

Cartridge brass consists of 70% copper and 30% zinc. Personally, I think you should listen to a chemical engineer and not use Brasso: "It's the copper in the alloy that ammonia dissolves: "Attack takes the form of reaction between ammonia and copper to form the cuprammonium ion, formula [Cu(NH3)4], a chemical complex which is water-soluble, and hence washed from the growing cracks". Just saying.

Don

[Unclenick]

After rereading the Wikipedia article I linked to, I am more convinced it is a bad idea to use Brasso or other ammoniated cleaners on it, despite the relatively brief exposure. If you do, what is protecting you is not case annealing but the fact you are not storing the brass in high humidity.

Below is a Wikipedia photo of a season cracked case by contributor DrHenley, taken 2003 and uploaded to the Wikipedia in 2010 and shared here under the Wiki Commons rules for sharing images. His description says:

Originally Posted by DrHensley

The case had been polished with Brasso, which contains ammonia, and then stored in high humidity for several years.

What you can learn from that image is that annealing, alone, does not prevent season cracking unless there is little or no stress from a seated bullet stretching the brass. It does nothing to prevent weakening of the brass by ammonia and moisture. It just reduces the total amount of stress from work hardening plus a bullet expanding the neck stress to just the latter, alone, so it takes longer for cracks to appear.

The military loaded its old 30-06 by painting a solution of asphaltum (pitch) and mineral spirits on the inside of case necks and letting the mineral spirits dry off. After the pitch dried, the bullet was seated. The asphaltum gripped the bullet, but there is no stress on the neck from an interference fit as is used in commercial ammunition and handloading today. I have pulled down both 1964 National Match ammunition and 1920's and 30's M1 Ball ammunition, and except for the crimp in the later, they are made the same way. If you use mineral spirits to remove the pitch from the bullet and from inside the neck of the case (and the crimp from the M1 Ball), you find the bullet is a slip-fit into the case neck and you can easily move it in or out by hand. The pitch, after drying, is like a high viscosity semi-liquid and the presence of the bullet flattens it out, so you don't have as much radial pressure against the inside of the neck, stressing it, as holding a bullet by an interference fit with the neck does. Annealing only prevents season cracking under the condition that there isn't significant stress on the neck from a bullet seated under it.

The other factor with military ammunition is that in the 1920's, Hatcher put polished cases (cleaned by dipping in 5% citric acid solution and then tumbling them) as the original arsenal practice had been and took them and some cases that had not been polished after manufacturing and set them on the roof of the Frankford Arsenal for a year. At the time, the atmosphere in that part of Philadelphia was quite corrosive due to chemical plants and sulfur from coal burning in the air. After that year passed, the polished brass was eaten away but the unpolished brass was still in good shape, illustrating that the oxides from production and annealing were actually good protection for the brass. This will have helped resist ammonia as well, by creating a kind of sacrificial oxide coating. So this is another arena in which the military ammunition's immunity to season cracking is unlike what you get in most commercial ammunition. Only cases like Lapua or IMI that have the annealing stain and oxides intact will have that added corrosion resistance.

So, what's going on with ammonia?

The name "season cracking" comes from the fact the problem would appear on cartridges during the monsoon season, when humidity was high enough to keep ammonia and copper compounds ionized. That allows surface ammonia damage to spread into the metal in the same way rust grows to pits. Just as rust will not occur on steel in low humidities, neither will ammonia damage continue to progress below the surface of a copper alloy in its absence. So it wasn't the ammonia exposure during the monsoon season that weakened the brass to make it split then. Rather, the high humidity allows ammonia damage at the surface to penetrate deep into the brass by ionizing it. It was the near 100% relative humidity during that season's constant rains and was reasly what caused the damage to progress to the point the necks split the necks.

Anyway, the lesson here is that short exposure to ammonia in Brasso will likely not harm your cases if you don't keep the polished brass in anything but lower humidities. However, if you do take it out into high humidity subsequently, the possibility of season cracking returns, as it may activate the ammonia damage at the surface and have it start penetrating deeper into the neck. It may not be weak enough to split spontaneously, but may, instead, split on firing.

Bottom line, ammonia and humidity work together to weaken brass. Splitting is caused by stress in brass that has been thus weakened. It may be hard to tell if a split neck observed after firing occurred entirely because of overworking the brass without annealing or if the weakening was partly caused by ammonia and humidity exposure.


Oxides

In the first photo below, you can see, especially on the left end, black cupric oxide behind verdisgris and blooming. This was caused when the brass got wet in a garage and stayed that way for a long time. Below it is the brass after cleaning in a heated ultrasonic bath in a 5% citric acid solution. There is pink from cuprous oxide left behind on some of them, but it is very thin and polishes off in the tumbler in about 15 minutes. I mounted a needle on a dial indicator and probed the pits from the oxide and about 0.002" was the deepest. The black oxide did not get below the surface. All that brass was subsequently loaded and fired repeatedly without incident.

[Roamin_Wade]

I’d like to report that I’ve done 20 30 cal Carbine rounds and 20 30-06 rounds and they came out pretty dang good. I think the brass may be clad with a topical layer of corrosion resistant alloy because where the heavier spots were it is a dull color and where it was superficial corrosion it is shiny as a new round. I’m not certain on that part but I know aluminum on aircraft have a layer of alclad (pure aluminum I think) on top of the aluminum alloy below that layer. I’m going to replace media with new and see if it will polish all of it up. I borrowed a tumbler and have been using what was in there until now. I’ve been taking pics but as of yet I’m unable to post in here.

[Roamin_Wade]

How long does it take to polish up ordinary empty 30-06 shells? To get these to look like I’m getting them has been taking around 6 hours a batch.

[USSR]

Roamin_Wade,

A little advice: add a capful of Nu Finish car wax followed by a capful of mineral spirits to your walnut media. Cuts down on the tumbling time and the brass comes out nicer.

Don