Tumbling loaded ammo

[Jim]

Many moons ago(MANY moons!), I tumbled some loaded ammo. When I shot it(rifle ammo), the accuracy went out the window. I asked a knowledgable loader about this and was told that tumbling can mechanically break down the powder granules causing the burn speed to change drastically. Just thought I'd mention this as I saw a post recently where it was mentioned about tumbling loaded ammo. I don't do that anymore.

[sargenv]

Um.. there are a LOT of people who do tumble their ammo. Usually people who process their brass through a progressive loader and use one of the spray on lubes.

Considering that loaded ammo has been "Tumbled" since it left the factory where it was packed by machines into boxes, those boxes then get palleted, then forklifts and other machinery moves said pallet onto truck or rail, then it gets jostled around in transit, then it gets taken off of the pallets, out of the cases, and then gets placed on the shelf where you and I may take a look at it, fondle it and or put it into or take it out of our carts (if we decide we want it or not) and then we take it home usually in some sort of vehicle, before we take it to the range, load it into a rifle, and then fire it..

Having said all that.. a few minutes in a tumbler likely will not degrade accuracy all that much.. since the powder you just loaded into the case likely went through something similar to above to get to your shelf before you measured it into your cases... :)

It may have had something else effect it rather than the tumbling in the tumbler to degrade accuracy.. and personally I think that is likely the case..

If you look around on other gun forums, the general consensus is that tumbling ammo by and large doesn't do much.. but as usual, ymmv :)

[pumpguy]

I always heard that commercial loaders tumble it for looks before it's packaged.

[Ed Barrett]

Commercial ammo is tumbled after loading. If you don't over do it I don't think it would hurt reloads.

[felix]

It should not hurt ball powder. I'd be very leary with any fast burning flake type. ... felix

[Ricochet]

Factories tumble pistol cartridges loaded with those, too. The flakes are light, and double base powder's quite plastic.

[KYCaster]

In my early days of loading 45ACP for USPSA competition I tumbled my ammo to remove the excess soft lube I was using. The stuff got on everything and would build up in the chamber and cause feeding problems.

Ammo loaded with W231 tumbled for one hour would show a very slight increase in average velocity and a slight decrease in ES and SD. The results were consistant and repeatable.

When I found a good lube I no longer saw a need to tumble ammo since it was clean and ready to shoot as it came off the loader.

Now I load 223 for three gun competition and rather than tumble the ammo to remove sizing lube I run the brass through the machine with only the size die in place then tumble and load the clean cases leaving out the sizing die. I'd rather do that than do the testing necessary to determine the effect of tumbling on the powder.

I have tumbled some rifle ammo and shot it with no noticable negative effect but have not done any testing to quantify the effect. I'm just not comfortable with the practice and choose to avoid it.

Jerry

[danski26]

tumbling loaded ammo for a short time to clean lube off cases does not hurt the powder inside. I know the comercial loader that I live by does it and I believe all factories do it too.

[Jim]

Well, I guess I'm odd man out.

[Casting Timmy]

If you're trying to clean off lube on the case or off the bullets, you can put the ammo in a small bucket and move it around with your hand. It'll clean off the excess and won't cause problems to your powder.

I do agree with some people above that you should be able to tumble it for a little. The back of an 18 wheeler has to really shake that powder in the cases around. Not to mention all the other things that happens to a loadedround sometimes before it gets shot.

[405]

Well, I guess I'm odd man out.

I guess we're the two men out :drinks:

Who knows what excess movement will do to powder or the coating on powder. Just another variable added to reloading where there are already too many to begin with :???:

Lube comes off pretty easy with some acetone on a paper towel. I don't tumble/vibrate clean before loading either... who needs media stuck in flash holes and polishing compound inside cases. Never found cosmetics to do much one way or another :)

[Dale53]

Perhaps "The" answer is NOT whether we should tumble or not. Perhaps "The" answer is HOW LONG.

I save old media and use it with a couple of caps of mineral spirits in a large Dillon vibratory tumbler to tumble loaded ammo FIFTEEN MINUTES, no shorter and no longer. Further, I believe it is important to remove the loaded rounds immediately after tumbling is finished. I don't want the fumes from the mineral spirits to possibly seep into the primers and damage them.

Using this method I can have extremely nice, clean ammo and it has NO effect on the loaded round.

However, if one were to tumble loaded ammo for extended periods I DO believe that damage could occur.

I look at it as a matter of degree...

FWIW

Dale53

[watkibe]

Most cast boolit loads are reduced. The smaller amount of powder in the case will tumble about much more than factory loads, which are usually close to 100% case density. Think about it, shake a compressed load, and the powder doesn't move, does it ? What about a case that's a quarter full ? Shake it, and you can hear the powder moving inside.
My concern would be that the deterrent coatings would be compromised (reduced) and the powder would burn more quickly.
I admit that I have never tested it out, but the results of my "thought experiment" were enough to convince me not to tumble loaded ammo. There are plenty of ways to avoid the need to do so.

[Ricochet]

Most factory loads are not 100% density. Shake them and you can hear the powder.

This issue's not worth arguing over IMO. Do what you feel comfortable with and don't do what you think's risky. I've never tumbled a cartridge, empty or loaded, and I see no good reason to start.

[troy_mclure]

i read a similar topic on tfl or gbo a year or so, one of the big name gun writers did an article in which he tumbled various finished rounds for MONTHS!!!

when he pulled the powder and examined it under magnification he found no discernible break down of powders.

any changes are likely to be due to bullet moving in the case because of light/no crimp.

[1Shirt]

I just have never seen a need for it quite frankly.
1Shirt!:coffeecom

[Ed Barrett]

I think the best method would be to make a batch of rounds and tumble half of them for 24 hours and keeping them seperated take them to the range. If the tumbled are have the same accuracy and speed over a chrono then it's a mute point. If the tumbled rounds are more accurate, in 6 months all the benchrest shooters will be tumbling their rounds for 24 hours.

[mroliver77]

I got treated pretty bad on the old forum, one time for mentioning this. I had some milsurp 8mm
that was pretty cruddy and tu,bled it for 12 hours to clean it. It shot just fine. After the "exspurts" had chastised me I tumbled some 24 hrs and compared with powder pulled from un tumbled rounds.
Even under magnification there was no difference and no evidence of coating coming off. I tumbled some for days with the same outcome and reported my findings. Guys that had never tried this still called me a fool. If I listened to ALL the advice I have read on forums, I would prolly never had started reloading!
Like Dale, my biggest concern is the spirits contaminating the primer, so a short cleaning trip is all my BULK reloads get. YMMV
JAY

[Blazin]

John Pride, winner of many PPC and Bianchi Cup matches, tumbled his ammo for 1 hour:
http://www.shootingpride.com/4bc.html

[shooterg]

Like mroliver77, I have tumbled grungy surplus ammo(in my case over 4000 rounds of ball USGI .308) with no difference in before and after accuracy. I haven't tumble newly loaded stuff as I clean sized brass before priming , but it looks like an interesting comparison test for someone !

[Jim]

Well, I have no clue what caused the problem I had, but, obviously, it wasn't from tumbling the ammo.
OK guys, I'm sold.

[JSnover]

Ammunition is tumbled quite a bit during the T&E to make sure it can withstand rough handling, long road trips, etc. Samples are fired afterwards to make sure the pressure is still in the normal range.