This is a discussion on ScotchBrite on corroded brass. within the Ammunition forums, part of the M14 M1A Forum category; Originally Posted by tywest
Mussa red it on da innernets
must be true if it's on the net.......
It's a safety issue when you tumble live ammo.
I only tumber 'wet', using ceramic media. I have 'brass' that I have reloaded many-many times with no issue.
Been reload'n for over 45+ yrs.
If you anneal the case neck area of your bottle neck rifle brass, you can get many reloads from them http://www.bench-source.com/id81.html
Agreed. Just to be clear I wasn't suggesting tumbling loaded ammo. I was comparing the abrasive qualities of tumbling to SB. Suggesting that continued tumbling of cases could be more damaging than a one time use of SB to take off some corrosion.
I use SB for a quick once over corrosion spots then odorless mineral spirits on a shop towel. Cleaned up many K of HXP and DAG and haven't had a problem yet. I save the aggressive cleaning for the tumbler after firing and before reloading.
I don't clean much loaded ammo. I have cleaned some dirty brass prior to reloading it.
I use one of the Lee trimmer pieces. I chuck it in the drill, insert the rim of the brass case, tighten up the ring that locks the brass into the holder and spin it with the drill will holding some 0000 steel wool onto the surface of the brass. This makes short work of any corrosion on the brass that the standard run through the brass polisher didn't remove.
Some people (I never have but I've thought about it) put liquid car wax into the brass polisher when running their cases through it. If this leaves a very thing coat of wax on the surface of the brass then one of the benefits should be reduced corrosion build up over time while in storage. Maybe, just maybe, a few minutes in a brass polisher with some wax/polishing media with your long term (SHTF) ammo stash would be a good idea before you seal it upin the cans.
Judging by the MSDS, the abrasive in a SB pad is almost entirely aluminum oxide; approx. 300 - 400 times as much as quartz silica. Seems like a non-issue to me (as a function of how much quartz silica is likely to interact with the brass casing).
Bought 20 rounds 1973 dated M118 last week. Half of them were corroded. Started off with steel wool, then thought about using the Dremel with a steel wire brush attached. Took all the corrosion right off, but did I ruin the cases by doing so? I did not go crazy with it to the point where I started to remove material from the brass.
Not that vibration would break down smokeless powders anyway, but media (mostly) moves AROUND the brass/loaded round--But, for pete's sake, think about ammo cans on a military tracked vehicle traveling hundreds/thousands of miles on or off roads.. lol).
PS (added). The vibration on the military ammo in cans on Armored vehicles would be MORE/GREATER than that upon loaded ammo in a (mere) vibratory tumbler.
PSS, I am pretty sure the "Tumbler of Truth" guy also CHRONO'ed the ammo (in addition to 30X photography-which clearly showed no visible degradation). Results were no difference after a WEEK (best I recall) of tumbling.
Very few things in this world are absolute and I suspect that saying that powder can't be damaged with tumbling is probably not one of those absolutes.
I doubt if any of us, including the guy that posted the powder pictures, are qualified to recognize what good or bad powder looks like. What's more, since one of the arguments is that the coatings are worn off of the powder granules, we couldn't necessarily determine all the effects of tumbling from a picture. The burn characteristics of smokeless powders are controlled by chemical constituency (including any coatings used to control burn rates), shape, and size. All I can say is that, considering that the powder is restricted by the small confines of the case, tumbling probably doesn't do any harm but I don't think that it helps either; and I'm sure that if you went to an extreme in either length of time or amount of vigor there would be some negative effect on the powder.
Adam forwarded your inquiry to me, and I'll be happy to answer. The short answer is, no, it's not going to cause a problem, but I do want to cover a few things just to be safe. The slightly longer answer is yes, it could. Tumbling of loaded ammunition is a common practice for ammo manufacturers, and it's done all the time. The key is, they don't do it for very long; usually nothing more than required to remove any traces of lube from the loaded ammunition, or whatever else may need to be accomplished. I normally do this with large lots of pistol ammunition if I've bulk loaded them on a progressive press. Again, the key is, they're run for a very short period of time, never more than 10 minutes. You're obviously familiar with powder "construction" and the application of deterrent coatings such as graphite or dinitrotoluene (DNT), and I assume your concern stems from the possible removal of or damage to this coating. Actually, this is precisely how many of these coatings are applied to begin with, and the powder goes through several tumblings during its production. In short, damaging it via this same process is fairly unlikely, especially once the powder is contained in a loaded cartridge.
This said, anything can be overdone. Tumbling cartridges for an excessive length of time, or in too vigorous a tumbler could be detrimental. I can't hazard a guess as to how long this may take, as I suspect there will be several variables coming into play. The bottom line is, minimum tumbling, in as gentle a process as will accomplish the task. For my own loadings, as I said before, I use ten minutes as my own personal maximum, in a vibratory tumbler. Loaded cartridges will likely see much more severe treatment than this in the field (bouncing around in SUVs off road, etc.) so I personally regard this as an acceptable limit.
Longer tumbling times and/or exceptionally rough tumbling methods could, theoretically, create problems. These may relate to the deterrent coatings, or to the possibility of external damage . The potential for accidental ignition via a primer being impacted by an FMJ, that sort of thing. I've never heard of such an occurrence, but I wouldn't discount it, either. The key here is some moderation and common sense.
I hope this answers your concerns, but if you'd like to address anything more specifically, I'd be happy to discuss this with you further. Please feel free to contact us again, anytime. As always, we're more than happy to be of service.
And the same person posted this from another manufacturer's representative
Tumbling loaded cartridges is not a good idea. The powder is mechanically degraded by friction creating a very fine dust-like powder and reducing the size of the powder kernels both of which increase the burn speed of the propellant in the cartridge. If the propellant has an externally applied deterrent coating, this coating may also be removed from the individual powder kernels which, again, increases the burn speed of the powder. Increases in burn speed of the powder will cause pressures to escalate along with the degree of degradation of the powder by the mechanical action of tumbling or vibration.
In other words, it is not recommended to tumble or vibrate loaded ammo. There can be no positive outcome from doing this, only negative outcomes.
Customer Service Manager
Hodgdon Family of Fine Propellants
Hodgdon Smokeless Powder
IMR Powder Company
Winchester Smokeless Propellants
Since a lot of people have tumbled live cartridges and there seems to be no consistently provable problems associated with this practice I would say that it appears to be safe to do so. But until somebody does a truly scientific study on the effects of tumbling cartridges I wont say that nothing happens to the powder, it just seems like nothing happens that is bad enough to cause alarm.