Tumbling finished rounds to remove lube etc

[Schwing]

There was an earlier thread about whether or not it is a good idea to tumble loaded rounds or not. I apologize to the thread creator since I can't seem to find it and started this one.

I have tumbled mine since I started reloading about a year ago. I haven't noticed any difference between the rounds but the idea of the powder grinding down and the burn rate changing made me wonder so I did a test. This is with the largest flake powder I have (Hi skor 800x). I tumbled a finished .357 round with about 8 grains of powder in with my brass for 6 hours (which is 6 times longer than I would tumble my finished rounds). I pulled the bullet and dumped the powder on paper for contrast. I then put about 8 grains of powder straight from the container onto the paper to look at the difference. The results are below. I obviously know which is which and I CAN tell a difference but I want to see what you all think. One of the pictures is tumbled, one is not. I know that difference sized cartridges/powder/loads will be slightly different so this is just one example.

 

[steve4102]

No difference!
#1 is tumbled.

Tested under Magnification.

http://www.ar15.com/forums/t_6_42/303242_.html&page=1

 

[Walkalong]

Great thread over there steve4102.


Here is a thread where snuffy and I tumbled some live ammo when the question came up..

 

[steve4102]

Thanks for the link Walk, now I have something to do/read next week. I'm bored, man, bored.

 

[Ironbar]

I have tumbled live rounds ever since I read that article at ar15.com. I have never had a single problem with any round whatsoever. They all went bang.

Nuff' said.

 

[Schwing]

Steve,
That is, hands down, the coolest test I have seen done to debunk a common reloading myth. As someone fairly new to reloading, I find myself often wondering about all of these common practices that people follow simply because it has been done that way or not done that way for decades.

I used to work in a CNC shop and we tumbled almost everything we made to clean it up and make it look pretty. I had a REALLY hard time hand cleaning all of my cartridges but am far to OCD to just let them be dirty. I think that test will let me do this with no worries at all.

Now you really have me wanting to find my old microscope in storage. Those images are pretty spectacular. Thanks for the link!

 

[Hard_Cast]

Even before I read down the post, I was guessing ! was tumbled and 2 was not. There are more specks in 1 and some cut flakes. I think had both been thrown from powder thrower, there's be an even number of cut flakes.

I seriously doubt this has any appreciable effect, my only concerns are for buildup of dust on lead bullets sticking to their 'wax'. That being said, I was tumbling some right now

Patrick