Tumbling loaded rounds

[Red Ryder]

I recently had all the primers blow up in my 650. No injuries to me and Dillon is sending free replacement parts. Needless to say, I am nervous now. I want to know if anyone has "First Hand Knowledge" of any accidents while tumbling loaded rounds? I don't want anymore surprizes! I like tumbling my loaded rounds because they end up so clean. I found no supporting evidence using the "search button" (ok Grumpy one!) of first hand accounts of bullets going off, just fear.

[CraigS.]

Many people, including myself tumble their loaded pistol rounds to remove case lube.

it takes a hard impact to ignite primers.

[whistlepig]

I take it from your post you refer to a primer being struck in the tumbler in such a way to set off a round.... I am not aware of any detonations in a tumbler. The old adage of not tumbling loaded rounds actually has merit (maybe?) for a different reason.

If you were to tumble loaded rounds for a short period of time to clean them up, you will probably never see a problem.

The issue is, does powder suffer damage (a change of shape, or a frature of the individual piece of powder) to an extent to adversly affect pressure? If powder is changed in shape and/or size, the burning rate is affected, ergo pressure is affected. The change could be less pressure and velocity (what you talkin bout i no makee major???) or more pressure... (anybody see where the slide went?? I can't hear anything.....) Some loaders advocate this doesn't happen and a link from another post http://www.ar15.com/forums/topic.html?b=6&f=42&t=303242&page=1 has some fascinating observations on this. It is worth looking at.

I actually have seen damaged powder and while I don't know tumbling caused it, I do believe it is a contributing factor... 3 years or so ago, I was one of several shooters who shot a quantity of military surplus .308 rifle ammo in M1As. The total amount of rounds expended from this ammo was between 1000 and 2000 rounds over multiple shooting sessions. The intent was to do high volume practice with a more cost effective round. Ammo was noted to have poor ballistic perfomance, grouped like a drunk throwing rocks. A few keyholes were observed. Other shooters and I saw low pressure signs, like brass barely ejecting and 2 FTE with the empty never making it to the point of being ejected and then being re-chambered. Classic High pressure signs were also noted at times. Rounds were chrono'd and results were all over the place. Some research was in order. 10 rounds were pulled and the projectiles, brass and powder inspected. Bullets were classic 147 and 150 grain FMJ. They looked fine, but with some powder noted to be stuck to the bases, sometimes in clumps. The brass looked good with consistent necks and they case gauged fine. The powder was another story... It appeared to have started life as a stick powder but what was left in a complete charge from every case was every size chunk you could imagine from the original stick size to almost a dust. Several examples showed color changes as well. 50 more rounds were randomly selected from the remaing inventory and all showed damaged/degraded powder.

We investigated the background with our supplier and actually spoke to the importer. We found the importer to be helpful and curious as well. The rounds were originally British in origin, believed to be from the Radway Green Arsenal (hope thats right, can't remember spelling) and had been supplied to various miitary and governement agencies in other countries that were members of the British Empire. Upon importation for resale here, the rounds were found to have an extreme dingy appearance. The importer tumbled the rounds to clean up the appearance. The staff did not state the time spent in the tumbler, but did acknowledge that it was a lot of time. The importer declined comment on the size of tumbler and the media. The importer pulled some that they had on hand, both tumbled and not yet tumbled. The staff stated that the non-tumbled rounds showed a color change and some clumping, the powder was uniform in size and structure. The staff did see the same damage to powder in tumbled rounds that we did. The importer did ask to have the damaged rounds back and provided us with a credit. I think that age played a huge role in the above conditions and who knows what the storage conditions were, but I still have have decided that no good can come from tumbling loaded rounds. In high volume pistol I just tumble dirty brass to a clean condition (not shiny) and then go straight to the Dillon. In precision rifle I do so much case prep I dont want them banging around together after they are loaded.

Not Disparaging Radway Green surplus. We have some that dates from the late 60's that had been stored in good conditions in the original ammo cans. Looks great, shoots great. We even pulled a few after the above problem and found the powder to look new and perfect.

[AnthonyL]

I tumble the finished live rounds for 30 mins after loading is complete to remove any case lube, grease, etc from the process. It also puts a nice final shine on them. Never had an issue, and neither have my friends.

[Philo_Beddoe]

The instructions that came with my dillon tumbler said it was ok to tumble live rounds for no more then 15 minutes to remove case lube. Which is exactly what I do with zero problems.

Edited April 20, 2011 by Philo_Beddoe

[BBBB]

I tumble mine for 20 minutes and have never had a problem. I think an interesting experiment would be something like the following:

- clean 10 rounds by hand

- tumble 10 rounds for 15 minutes

- tumble 10 rounds for 30 minutes

- tumble 10 rounds for 1 hour

- tumble 10 rounds for 2 hours

- longer times of desired

Chrono these and note average velocity and SD for each batch. Obviously you would stop if you did start to see significant changes or you felt something was becoming unsafe. You could argue that the test would only be valid with that load (or maybe that powder) but it would still be interesting to know.

If I ever do it, I'll post the results.

[kevin c]

I did do that test, using N320 for a major PF Limited load.

I got a small increase in SD, but no change in mean velocity.

I don't tumble off the lube anymore, not because of concerns about the load, but more because less time bent over the tumbler and separator was appreciated by my back. If I take it off, I do a rubdown with an old towel sprayed with rubbing alcohol.