Any truth in this?

[Wild Bill 7]

I use to do the same as bmortell with the exception I would spritz a little mineral sprits on the towel first. Cleans the excess lube off post haste. Now I powder coat so I don't have to do that anymore.

[fatelk]

when im done making ammo i just set the pile in the middle of a full size old bath towel, grab each ends bunched up pulled tight, then tumble them back in forth inside the towel. its enough to wipe off extra lube or those tiny brass shaving from case mouths

Unless someone makes a chart of pressure data with every type of powder vs time tumbled im not gonna feel safe with some anecdotal evidence. Theres pobably some powders where you could wear off the outer layer and it dont change much, others might change a bunch, im not going to guess and check i kinda like my face where its at

They say you can't prove a negative...

I've been following this subject for years, thought it was interesting back when I used dry tumblers. A number of guys online really got into it, tumbling live ammo of various calibers with various powders sometimes days on end, using scientific controls, magnified photos, and chronograph results. To be honest it was all pretty convincing. At least it convinced me that the short amount of time I tumbled my ammo was nothing I was going to worry about, at all. I never saw any evidence to the contrary, only theories, worries, and what-ifs.

That's not to say that something bad couldn't happen under unforeseen circumstances, so your point is definitely valid; it's just that I was personally comfortable with what I was doing, and it worked for me.

That said, I really can't blame anyone for erring on the side of caution. That is often a wise course of action. If you're not comfortable tumbling, and what you do works well for you, then it's all for the better!

I also have to add: did I mention how much I love powder coated bullets?

[Peregrine]

This is a really easy one to test I think. Load a bunch of identical ammo, tumble groups of 5 rounds for a varying amount of time, test velocity against each other and a control.

Use a middle of the road powder charge so dramatic overpressure isn't a concern. And it shouldn't be.

I'd do it myself but after some reading and a little thought I'm pretty sure it doesn't make a difference. I don't tumble loaded ammo myself anyways but that's just because I don't see a need.

[Rcmaveric]

Never new there was a controversy. If my calibrated eye says the loaded rounds need a cleaning, then i give them a cleaning.

Sent from my SM-G950U using Tapatalk

[kevin c]

This is a really easy one to test I think. Load a bunch of identical ammo, tumble groups of 5 rounds for a varying amount of time, test velocity against each other and a control.

Use a middle of the road powder charge so dramatic overpressure isn't a concern. And it shouldn't be.

I'd do it myself but after some reading and a little thought I'm pretty sure it doesn't make a difference. I don't tumble loaded ammo myself anyways but that's just because I don't see a need.

I am one of those who actually tried this. I used 180 grain 40 S&W slugs over N320. I think I went up to 30 minutes in a vibratory tumbler filled with a mix of corn cob and walnut hull. I put enough rounds in at the beginning to rattle my teeth with the racket when I turned it on. Short version is that there wasn't any appreciable average velocity change, but there was more spread in the SD.

So I quit doing that. I kinda like the single digit SD's I can now get just using the aforementioned towel hammock with a few spirits of rubbing alcohol.

[gwpercle]

Everyone here is making good points, so I just sent an email to Hogdon, asking them this very question. If and when I hear back from them I’ll post what they say.
Thanks,
Paul

Good idea , whatever Hodgdon says I will accept .
Gary

[gwpercle]

I am one of those who actually tried this. I used 180 grain 40 S&W slugs over N320. I think I went up to 30 minutes in a vibratory tumbler filled with a mix of corn cob and walnut hull. I put enough rounds in at the beginning to rattle my teeth with the racket when I turned it on. Short version is that there wasn't any appreciable average velocity change, but there was more spread in the SD.

So I quit doing that. I kinda like the single digit SD's I can now get just using the aforementioned towel hammock with a few spirits of rubbing alcohol.

Now that info is rather eye opening...didn't expect it. Maybe tumbling loaded rounds is not the best thing to do.
Thanks for the post Kevin,
Gary

[robg]

its not a problem .if it was how could you transport ammunition ?

[owejia]

Best answer so far in this discussion.

[mdi]

They say you can't prove a negative...

I've been following this subject for years, thought it was interesting back when I used dry tumblers. A number of guys online really got into it, tumbling live ammo of various calibers with various powders sometimes days on end, using scientific controls, magnified photos, and chronograph results. To be honest it was all pretty convincing. At least it convinced me that the short amount of time I tumbled my ammo was nothing I was going to worry about, at all. I never saw any evidence to the contrary, only theories, worries, and what-ifs.

That's not to say that something bad couldn't happen under unforeseen circumstances, so your point is definitely valid; it's just that I was personally comfortable with what I was doing, and it worked for me.

That said, I really can't blame anyone for erring on the side of caution. That is often a wise course of action. If you're not comfortable tumbling, and what you do works well for you, then it's all for the better!

I also have to add: did I mention how much I love powder coated bullets?

I remember one of those experiments mentioned. The tester made up a few hundred .223 rounds, all the same. H tumbled a bunch for a few hours then shot a few over is chrony and disassembled a few. He inspected the powder under a microscope and compared to some fresh powder. He continued this experiment each time adding to the tumbling time. He worked up to several days, 24 hrs per day and the overall results were no change. Microscopic visual inspection and velocity testing (can't remember if accuracy was recorded) were virtually unchanged, or no more differences than any session to session variations.

One point usually brought up was how the armed forces shipped their ammo; via plane, train , truck, boat, jeep, mule and down to the grunt humping a bandoleer/pouch fill of ammo. If all this vibration, jostling for who knows how long, had any effect on ammo performance, the ammo would not be acceptable for use by any branch of the service...

[bmortell]

I have heard to change carry ammo yearly from multiple sources and their reasoning was that its being transported and shaking around for that long so I wouldn't say its unheard of

[MT Gianni]

While I don't do it the factories do.

[Alferd Packer]

What about all the war ammo shippped over the ocean in the holds of zig zag convoys that were tossed by the rocking and vibration thru the ship's being tossed by waves back and forth.
Then a lot of that ammo came back by ocean trip too.
Also bouncing in the bed of a truck or even in an ammo box in armored vehicles.Not a smooth ride either.

[Peregrine]

Short version is that there wasn't any appreciable average velocity change, but there was more spread in the SD.

So I quit doing that. I kinda like the single digit SD's I can now get just using the aforementioned towel hammock with a few spirits of rubbing alcohol.

That's pretty interesting, although my theory would be that those SD changes might be due to seating depth variations due to bullets being bumped inwards/vibrated outwards on not changes to the structure of the powder.

Frankly my attention is more occupied by being impressed you get single digit SD's with .40S&W, and even more so that whatever shooting you're doing with it seems to require that attention.

[kevin c]

I take no credit; it's the N320: a stick powder that meters extremely well. Through my unmodified Dillon measure I can throw sets of ten consecutive charges that added together only vary +\- a tenth of a grain, and I've let the measure run empty and get the same weight drop for each throw down to the last partial. Same for 9mm. Many shooters in my sport using N320 report the same kind of numbers.

The irony is that we like the small SD not because we want super accurate ammo (the US version of action pistol has a max scoring zone that's about 6" by 11", shot at distances as close as point blank up to [rarely] 90 feet), but because very velocity consistent ammo allows us to run close to the power factor floor that affects the scoring value of hits. That's desireable because lower power factor generally means less recoil and therefore faster multiple shots.

Or you could just say we're a bunch of recoil sensitive wimps

ETA: good thought there on possible OAL changes from tumbling the rounds. Mebbe I'll try to test that when I put my press back together (waiting on parts from Dillon).

[Hickory]

This is a very interesting subject. And these are my thoughts.

If there is two or more loose objects coming in contact with each other and are in a state of motion [vibration] there must surely be a alteration in those objects. Even mountains will deteriorate to rocks and sand in time and they don't vibrate for it to happen.

But, we are talking about a container (cartridge) with loose powder, but what if the powder is not loose, but compressed even slightly? Or is it loose powder in the cartridge that susceptible to deterioration.

So, I ask myself, how much motion and for how long to cause any change in the burn rate of the powder? And are all loose powders in the cartridge affected the same way from being vibrated?

I sometimes wonder about the reason why some handguns suddenly blowup with light charges of loose powder. Could the cartridges have been run through a vibrator?

I don't tumble my ammunition after loading, this is an area where Murphy's Law might come into play, but I do wipe them down after loading.

[6bg6ga]

I've tumbled loaded cases for a long time. I like nice looking ammunition. Never had a problem doing it and I doubt that I ever will.

[trapper9260]

What about all the war ammo shippped over the ocean in the holds of zig zag convoys that were tossed by the rocking and vibration thru the ship's being tossed by waves back and forth.
Then a lot of that ammo came back by ocean trip too.
Also bouncing in the bed of a truck or even in an ammo box in armored vehicles.Not a smooth ride either.

The ship dose not rock as much as you think for the ammo to be move around like it would be in a tumbler. I know , I was in the navy and been in some rough seas that you had to tie yourself in your rack and see a metal office desk slid from one side of a room to another. Also when going up a flight of stairs you just wait for the ship to do down and you are on the next floor of the ship.
I do not tumble live ammo .I just wipe down the round after I load them. As for the tube in a lever gun. I just clean it when I clean the gun.There is really not much in the tube as long you take care of the ammo .

[Larry Gibson]

trapper9260

Perhaps a few days, weeks or even a full year deployment ride on/in a tracked vehicle with ammo (9mm upwards or 40 mm) sitting loose in ammo cans being vibrated as much or more than any commercial tumbler of vibrator will would change your mind......

[Larry Gibson]

This is a very interesting subject. And these are my thoughts.

If there is two or more loose objects coming in contact with each other and are in a state of motion [vibration] there must surely be a alteration in those objects. Even mountains will deteriorate to rocks and sand in time and they don't vibrate for it to happen.

But, we are talking about a container (cartridge) with loose powder, but what if the powder is not loose, but compressed even slightly? Or is it loose powder in the cartridge that susceptible to deterioration.

So, I ask myself, how much motion and for how long to cause any change in the burn rate of the powder? And are all loose powders in the cartridge affected the same way from being vibrated?

I sometimes wonder about the reason why some handguns suddenly blowup with light charges of loose powder. Could the cartridges have been run through a vibrator?

I don't tumble my ammunition after loading, this is an area where Murphy's Law might come into play, but I do wipe them down after loading.

That's the theory. However, many theories just do not pan out in reality.........