I read this in another post about throwing rounds into the tumbler to remove any tarnish and discolor from the brass of live rounds. Can this actually be done safely with loaded rounds? I know it takes alot to set off a primer, but always thought no way to tumbling live rounds. Period. Thoughts?
Tumbling Live Rounds?
- Thread starter Nosler06
- Start date
Limit vibratory tumbling to 1 or 2 minutes!
http://bulletin.accurateshooter.com/2008/09/why-you-should-not-tumble-clean-loaded-ammo/
Q. Is tumbling loaded ammunition dangerous?
Answer: “…Extensive tumbling can cause the breakdown of the powder grains. This would have two major effects. First, smaller grains will ignite more quickly than larger grains, and second the deterrent coating on the outside of the grains may be rubbed off and will be absent from any fractured edges which will cause the powder to burn more quickly raising pressures.
Tests run some years ago by a commercial entity did indicate that potentially dangerous changes in powder charge burning characteristics do take place after PROLONGED periods in either a vibratory or a tumbling cleaner.
The key word here is prolonged. Many manufacturers of ammunition do a final cleaning of their product either by tumbling or a vibratory process before boxing it for shipment. In no case is this allowed to exceed more than just a couple of minutes. The intent is not so much to “polish” but to remove any traces of contaminants which might in time leave marks on the finished product. There seems to be a consensus among the ammunition manufacturing engineers that a minute or two of vibratory cleaning has no discernable effect on burning rates, especially for loads that are compressed, or nearly so. However, all have emphasized the need for EXTREME CAUTION not to overdo the process.
They also pointed out that there is a considerable difference in effect on the powder charge depending on whether the process is by ‘tumbling’ or ‘vibrating’. It would appear that tumbling has less effect on the powder than vibrating, though this is mostly a matter of degree. The admonition to use EXTREME CAUTION to insure that the process never exceeds a couple of minutes applies equally to either process.”
http://bulletin.accurateshooter.com/2008/09/why-you-should-not-tumble-clean-loaded-ammo/
Q. Is tumbling loaded ammunition dangerous?
Answer: “…Extensive tumbling can cause the breakdown of the powder grains. This would have two major effects. First, smaller grains will ignite more quickly than larger grains, and second the deterrent coating on the outside of the grains may be rubbed off and will be absent from any fractured edges which will cause the powder to burn more quickly raising pressures.
Tests run some years ago by a commercial entity did indicate that potentially dangerous changes in powder charge burning characteristics do take place after PROLONGED periods in either a vibratory or a tumbling cleaner.
The key word here is prolonged. Many manufacturers of ammunition do a final cleaning of their product either by tumbling or a vibratory process before boxing it for shipment. In no case is this allowed to exceed more than just a couple of minutes. The intent is not so much to “polish” but to remove any traces of contaminants which might in time leave marks on the finished product. There seems to be a consensus among the ammunition manufacturing engineers that a minute or two of vibratory cleaning has no discernable effect on burning rates, especially for loads that are compressed, or nearly so. However, all have emphasized the need for EXTREME CAUTION not to overdo the process.
They also pointed out that there is a considerable difference in effect on the powder charge depending on whether the process is by ‘tumbling’ or ‘vibrating’. It would appear that tumbling has less effect on the powder than vibrating, though this is mostly a matter of degree. The admonition to use EXTREME CAUTION to insure that the process never exceeds a couple of minutes applies equally to either process.”
Anecdotal evidence only. No (even somewhat) scientific results. Just more spreading of the myth without any real testing.
I'm not saying they are wrong or right but they have absolutely no proof in that document either way. They are relying on myth and anecdote instead of repeatable tests.
Guys, I have spent time in a powder factory. At one step the powder is tumbled to coat the graphite and to try to round the cut edges a bit, so it will meter better. No matter how long the powder tumbles, the kernels do not break.
If you want to experiment load some stick powder in a case (mild load, so there is lots of room for the power to move around) and then tumble it for a week. Shoot it and some control ammo over a Chrony and see if you can see any difference,.
If you want to experiment load some stick powder in a case (mild load, so there is lots of room for the power to move around) and then tumble it for a week. Shoot it and some control ammo over a Chrony and see if you can see any difference,.
BattleRife
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Most of the discussion about tumbling live rounds centers around the powder breaking down. But now and again someone brings up the idea of a primer going off. The very idea leaves me scratching my head, because:
1- It takes a very strong, concentrated hit with a firing pin to set off a primer, how on earth is a soft bullet tip, brushing past under the ifluence of a flowing media, possibly going to get the energy to crush a primer? and;
2- Even if the seemingly impossible combination of factors actually came together so that one did go off, so what?
