Tumbling finished loads

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hossfly

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I read someone on some board say they tumbled finished rounds. I've never done that before. Are there any reasons not to?
 
It won't hurt a thing.
How do you think the factorys get new ammo so shiny?
That's right, they tumble it after loading it.

There is about a zero chance of one going off in the tumbler, and even if it did, it wouldn't hurt anything because the primer & case would be contained by the tumbler bowl & lid.

Just don't overdo it and forget and leave it in the tumbler three days or something and it will be fine.

I generally clean all my brass before loading, then tumble again after loading for 30 minutes or so to get all the sizing lube and fingerprints off.

The exception is lead bullet reloads as the bullet lube makes a mess with tumbler media dust stuck in it.

rc
 
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Rollin' Them Bones

If you do it, you should use a vibratory type versus a barrel type that rolls and actually "tumbles". It is generally not recommended because at the least it can cause the powder grains to abrade and degrade the coating (altering the burning characteristics and causing erratic/dangerous pressures), and obviously at worst setting off a round(s). Maybe not true Russian Roulette, but shooting craps for sure. I have done it briefly for dirty or sticky cases (from not cleaning lube off well enough), but I try to avoid it. I am a really crappy gambler... :rolleyes:
 
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I bet ammo in a Humvee or Blackhawk in Iraq gets more vibration in a day then your ammo ever will by cleaning it for 30 minutes in a tumbler!

rc
 
The unit I have would wear out fast loaded down with finished rounds. The motor wasn't designed to handle that kind of a load and it heats up bad enough as it is.
 
I bet ammo in a Humvee or Blackhawk in Iraq gets more vibration in a day then your ammo ever will by cleaning it for 30 minutes in a tumbler!

This is why I change out my carry ammo after about a year. The burn rate of the powder changes as it becomes more dustlike over time.
 
This is why I change out my carry ammo after about a year. The burn rate of the powder changes as it becomes more dustlike over time.

Ever pull down a few of your year old rounds and actually check just how dusty they are?

Just curious.
 
It's amazing how some people get their panties in a wad as soon as somebody mentions tumbling live ammo. The myth that the "POWDER IS GONNA GRIND ITSELF TO DUST" comes up. As does the "point of a bullet is gonna get detonated by another round". None of that will happen!

Powder is similar to a plastic. It's some tough stuff. Don't think so? Try to crush a chunk of extruded/stick powder! As for the retardant coating being "GROUND" off, by what? I certainly don't put grinding media in with my powder charge. Powder is also coated with graphite, to make it slippery so it will flow through measures easily. Soooooo a slippery, tough powder granual is going to grind itself against other chunks to dust?

As for one round detonating another, smokeless powder doesn't detonate, it burns at a progressive rate IF it's confined. Simply being inside a shell/cartridge is not confined. It HAS to be in a chamber, held by a bolt/recoil shield/breach, then struck with a lot of force by a pointed HARD firing pin. Where in a tumbler does those conditions exist?

Do I do it? Yes, when I'm running in full progressive mode on the dillon 650. I'm putting lubed brass in the case feeder, running them through the entire process,(.223). This leaves me with loaded, lube coated shells. 20 minutes in my FA tumbler, with untreated corn cob results in clean, shiny ammo, ready to be gauged and packed in boxes.
 
Typically, after a batch or reloading, from 9mm to .270 Win. I will dump them in the tumbler while I clean and put things away. Usually around twenty to thirty minutes. Takes care of any finger prints or smudges that accumulate while handleing.

RU
 
Stick Powders

At the risk of having my jockey's inspected, I believe the old caveats on tumbling were more intended for stick (extruded) powders. The granules, which are in no way chemically or characteristically similar to plastic (though they do contain chemicals called plasticizers), are coated with flame retardants to adjust burning rate, and are usually hollow, to allow burning to progress from two sides (for a detailed discussion see The Manufacture of Smokeless Powders and their Forensic Analysis: A Brief Review, http://www.fbi.gov/hq/lab/fsc/backissu/april2002/mccord.htm#composition). To suggest that a bit of tumbling will turn it to dust is incorrect. To suggest that granules do not abrade under tumbling is also incorrect. It's a matter of degree; a little is unlikely to do anything, a lot - well, how much is a lot? - may change things. Ball powders and flake powders are differently constructed and though less susceptible to abrasion, still, technically can abrade. Again, it's a matter of degree. Tumble any loaded round for an hour or so & I say it's unaffected, relatively. Two or three days? Might affect it. As for a round going off, chances are really low. But is there a chance? Yes. Probable? Maybe not, but possible. SAAMI (Sporting Arms and Ammunitaions Manufacturers' Institute, Inc., Flintlock Ridge Offiice Center, 11 Mile Hill Rd, Newtown, CT 06470-2359) comments on explosive characteristics of smokeless powder:

If burning smokeless powder is confined, gas pressure will rise and eventually can cause the container to burst. Under such circumstances, the bursting of a strong container creates effects similar to an explosion.​
Idiots make pipe bombs with Bullseye (Atlanta's Olympic Park bombing comes to mind), and whether you inaccurately label it a detonation, or accuretly describe it as an explosion, the victims won't be inclined to quibble. Chances of injury from a round popping off in a tumbler are very low as well - if a loaded round is cooked off in a fire, the case typically is propelled away at a velocity sufficient to bruise you ("you'll put your eye out, kid!") and the slug bounces around harmlessly (Newton's First Law). People have been killed by meteorites and swallowed up by sink holes, but I am resting comfortably in my chair without anxiety since the probablity likely is less than my chance of hitting the lottery.

Just goes to prove that for any possibility, the probability that it will provoke discussion is high (after all, this is The High Road.... )

Cheers to all bi-partisan respondents! :D

(right now I have to go check my tumbler... :rolleyes: )
 
I kinda have to. I lube size the case on a turret press then load primer, powder and bullet. I give it a little tumble to take the lube off.

Tom
 
It is generally not recommended because at the least it can cause the powder grains to abrade and degrade the coating (altering the burning characteristics and causing erratic/dangerous pressures), and obviously at worst setting off a round(s).

Thirty-five years ago load manuals contained a similar warning. Newer manuals do not. This debate surfaces about every three months on every board I visit. Several years ago, I contacted every powder manufacturer I could. I received three responses. All said basically the same thing: Can't hurt the powder. We tumble beyond anything the hobbyist ever could, but we can't recommend.

Here's a link to the same argument: http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1386281&page=2

One person made the observation that it was a problem, but the problem no longer existed. IIRC one lab rat conducted a series of tests.

If you're not comfortable doing it, don't do it.
 
Maj Dad, a couple of things;

If burning smokeless powder is confined, gas pressure will rise and eventually can cause the container to burst. Under such circumstances, the bursting of a strong container creates effects similar to an explosion.

The key word here is confined. The difference between a cartridge outside of a chamber with a bolt or whatever holding it there, and a pipe bomb is enormous. A cartridge, round or shell that somehow gets activated outside a chamber will simply bulge until the bullet moves, then it'll go PFFT,( like a sneaky fa*t). The primer if it fires will make a lot more noise than the powder. And it won't hurt anybody.

The granules, which are in no way chemically or characteristically similar to plastic (though they do contain chemicals called plasticizers), are coated with flame retardants to adjust burning rate, and are usually hollow, to allow burning to progress from two sides.

Maybe not plastic, but they're tough, not easily broken up. Also, the only stick powder that I know of that's a hollow stick is SR-4759. Maybe AA 5744 is too, since both are like the old smokeLESS powder first made in the 1890's. They were made to be as bulky as black powder. Their use now days is in the big black powder cases like the 45-70 to be bulky for higher load density. An example of a perforated disk is the new trail boss.

Here's some 4350 powder that was loaded in IIRC 30-06 cases. One was a once fired case, the other was new. Notice the new case shows no breakdown of the powder granuals These were tumbled in a vibratory tumbler for 5 hours. The powder DID remove some of the carbon fouling inside the fired case.

4350used%20and%20virgin%20cases.jpg

Here's a test I did with Reloader 19 in my 300 WSM. The load was at 85% density, so there was plenty of room for the powder to move around. This pic was at 3 hours of tumbling in a FA vibratory tumbler.

P1010024_edited.JPG


Then I again pulled a bullet on the same load after 15 hours;

P1010025_edited.JPG


Do you see any dust? Or broken granuals? If the deterrent coating was being rubbed off, then where did it go? I looked at it with a 10X magnifier, the powder looked the same even after 15 hours!

I also fired shells at 2 hrs,5,10 and 15 hours, five shots each, at targets, and over my chrono at the same time. Also a control set of rounds was not tumbled. Accuracy actually got better. Seeing no difference in powder appearance, I stopped tumbling at 15 hours.

I almost stopped the test after firing the 2 hr. shells. The velocity jumped about 700 fps in three of the five shots! It was high noon on a cloudless day, I believe I was getting some bullet glint, triggering the stop screen early. I took a break and discussed it with a shooting buddy. He said I was crazy if I continued the test. Well the appearance of the cases, and the recoil convinced me there was no problems. No primer flattening, and normal bolt lift. The next 5 were at 5 hours, they were the same area that the control group were reading. And the 10 hr. and 15 hours as well!

P1010026_edited.jpg

tumble%20groups.jpg
 
A cartridge, round or shell that somehow gets activated outside a chamber will simply bulge until the bullet moves, then it'll go PFFT,( like a sneaky fa*t). The primer if it fires will make a lot more noise than the powder. And it won't hurt anybody.

I've witnessed cases rupture. Was once fragged in the leg, but, as you mentioned, the bullet is harmless. I've never seen or heard of any sympathetic detonations. I cannot imagine brass fragments penetrating a tumbler bowl.
 
I have done testing with cook-off rounds that were not tightly confined.

I can tell you that rifle calibers simply burn the powder out, and in some cases will not even dislodge the bullet from the case. All the fire / pressure goes slowly out the flash hole.

Handgun calibers using fast powder will frag the cases every time.

It is the primer exiting the case at high velocity that is the most dangerous.

But even primers do not have a chance of making it through a tumbler bowl or lid.

rc
 
I can tell you that rifle calibers simply burn the powder out, and in some cases will not even dislodge the bullet from the case. All the fire / pressure goes slowly out the flash hole.

The ruptured cases I mentioned were from primer ignition. As a kid I remember the neat thing to do was throw 22 rounds against concrete. Caught a couple pieces of flying brass. Lucky we were never hit in the eye. Ah, the immortality of youth.
 
It would be unusual for a .22RF case to frag.

Here are some cook-off results.
As noted, primers are most dangerous.
Followed by RF cases.
Followed by CF pistol case frags.
The aluminum Blaser .357 case did punch through the sheet metal.
The brass cases frags didn't even dent it.

But, cook-off's have nothing to do with polishing loaded ammo, because they simply do not go off in a tumbler.

AmmoFire4.jpg

AmmoFire3.jpg

AmmoFire2.jpg

rc
 
When I was a kid I pulled the bullet and dumped the powder from a .243 ctg. I then proceded to heat up the case with my new torch in my bedroom. I never thought about the primer. When it blew it sounded like a .22 mag. from a revolver. The primer left the case and went thru an inch of southern white pine and ended up in my drawer. The shell casing went straight up and embeded itself in my parent's ceiling. I was deaf and blinded for a while and Mom was furious as one can imagine.

That was over 40 years ago and needless to say, I have the utmost respect for primers.
 
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