Tumble or no tumble your reloaded ammo? A new twist.

[TexasSeaRay]

I've been doing this experiment on "To tumble or not to tumble . . ."

For the most part and the majority of the time, I do not tumble my loaded ammo. Instead, I make sure my brass is polished and clean before I load it up.

But, over the past few years I've been reading about all the ills, evils and catastrophic world-ending probabilities that are just waiting to happen if you tumble your loaded ammo.

So I decided to start doing a little experimenting. There are already a few threads on this in the Handloading and Reloading area of TFL--what I'm posting now is simply a continuation of what happens when you have too much time on your hands and way too curious of a mind.

For this latest round, I loaded 52 rounds of .38 Special 158 gr Lead Round Nose (LRN) with 4.3 grains of Accurate Arms #2 and used Winchester Small Pistol primers. The cases are mixed.

I chose AA#2 because it is an extremely fine powder in terms of makeup and grade. It's a ball powder and my thinking was that a fine, small ball powder would be less affected by a long tumbling session (if it would be affected at all) than would a flake or extruded powder.

The previous portion of this ongoing experiment had an unexpected incident. The lead bullets took on a dark luster from the tumbling. At first glance, they appeared to have lost some metal compared to the untumbled rounds.

The tumbler I use is a Thumler's Tumbler and it is a rotary-style tumbler as opposed to a vibratory tumbler. For this round of experimenting, I tumbled 24 rounds for six hours in treated walnut media, then another six hours in untreated walnut media. This is my standard cleaning process for brass before I reload it. I like clean, shiny, like-new looking brass.

Here are the untumbled .38 Spcl 158 gr LRN rounds.



And here are the tumbled rounds. Note the darker color of the bullet itself.



Prior to heading to the range, I pulled a bullet after the tumbling was complete and put the calipers to it in order to compare it with the untumbled bullet. They were identical at both the base of the bullet and the front of the bullet. I then weighed the tumbled bullet and compared it with the untumbled bullet. Identical.

At the range, I shot several cylinders of normal wadcutters just to get a little powder and fouling in the barrel to level the playing field.

Next, I taped up two 3"x5" blank notecards to my target, then ran the target to 75 feet instead of my normal 50 feet. I wanted the extra 25 feet to help expose any differences there might be between the tumbled and untumbled rounds.

I alternated cylinders between tumbled and untumbled. I started with six rounds of untumbled, firing handheld at one notecard, then switched to six rounds of tumbled loads and fired at the opposing notecard.

Here are the results.

The untumbled rounds at 75 feet handheld.




And the tumbled rounds at 75 feet handheld.



Quite honestly, I couldn't feel or tell any difference in how one set of rounds fired over the other. The gun I used was my Smith & Wesson Model 686 with a 6-inch barrel.

Next phase in this thing, I guess I'm gonna start trying flake powders and see if the tumbling process affects the large powders. It sure didn't affect the AA#2.

Not sure what to make of all this, and I'm NOT recommending anyone tumble their loaded ammo, nor am I discouraging anyone. Just trying to draw some conclusions based on firsthand experience rather than third-person reports.

Jeff

[Dumpster Baby]

That's some great info there. I never knew for sure what the consequences of tumbling lead bullet ammo was. I know that the ammo manufacturers have tumbled billions of rounds of hunting ammo before they box it for us consumers.

It's interesting that the RNFP's cold flowed into RN's. I just bought 1K of that same RNFP bullet for .38 plinking loads, and some SWC's.

Now I know not to tumble them if I want to retain the as-designed bullet shape.

[Sevens]

I was able to come to a conclusion to your experiment:
Your plane fuel must be getting too expensive, and you have too much free time on your hands since you are grounded!

You already said the LAST time this came up that you were tired of this conversation... no matter what you do, or how well you conduct an experiment, someone is going to blast in here and tell you that the next Hiroshima is going to happen in Texas, at your range, or in your basement.

About the only thing we know for damn sure is that you are a helluva shot. Your 50 feet notecards are a waste of ammo, because most of the bullets never hit the paper... instead of hitting paper, they tend to go through the ragged hole in the middle of the card. So we'd hope to see some piss poor groups coming from your 75 feet notecards, but it's more of the same.

Come to think of it, here's another conclusion-- get rid of your two .30/30 lever guns and trade them in on S&W revolvers!

[2sigs]

TSR Great read, I live dangerous myself I tend to tumble alot of my rifle loads and some of my handgun ammo.

Here is what is missing from your experiment if I may? Velocity

Velocity is what comes to mind, including does it change when charge has been tumbled and is it + or - from standard non tumbled load

I am very interested in the outcome of the velocity test as particularly the rifle could suffer dramatic change in point of impact tumble vs. un-tumbled

I may just do a lil test of 20 charges of hand charged / weighed cartridges.

Place 5 on shelf and keep save from movement etc LOL

Place 5 in plastic carrier and toss in truck glove box til hunting season this fall

Place 5 in tumbler for 1hr as usual loaded ammo is tumbled

Place 5 in tumbler for 12hrs. VERY harsh tumble

Then shoot at 50yds. this fall and see FPS and Group size of ea. 5 shot

I don't mean to steal the thread but yours brings this up,
I will start a new thread to get thoughts and for input

-2sigs

[TexasSeaRay]

Sevens,

Weather has been kinda crappy around here for flying--at least on the days off I've had. So, only one thing to do and that's . . . GO SHOOTIN'!

If I ever find a shooting range that has its own landing strip, I'll be in real trouble.

DumpsterBaby--those flat nose didn't change into true round nose. I was doing a mix of bullets in this thing and forgot to take "before and after pictures" of the rounds that hadn't been tumbled, so I snapped those pictures basically to illustrate what the tumbling did the lead bullet color. It didn't affect shape in any fashion.

Sorry for any confusion.

2sigs--yep, I need to check velocity. My chrono crapped out a few years ago and I haven't bothered to replace it. I'll probably start shopping for one and then I can add a little bit of "scientific validity" to my curious mind when I get these urges to check on old wives tales.

Jeff

[Alleykat]

This "experiment" is largely irrelevant to the few minutes of tumbling that I do to remove case lube from loaded rounds. OF COURSE I don't tumble loaded rounds just for the fun of it.

[Shane Tuttle]

TSR,

Not to deviate from the perfomance figures from tumbling loaded ammo, but what kind of fouling are you getting from your 686?

Do you think there's a chemical reaction going on with the lead and the agent used in the tumbler?

If so, do you think the characteristics of fouling from the lead changes to some degree? This thought came to my head because some people make their own lead and there's more than a couple of lead variants/"alloys" used. IIRC, you like MasterCast bullets. Are these bullets that you used MasterCast's?

[TexasSeaRay]

Well now, here's the thing. . .

The LAST rounds I fired out of that 686 were the ones that had been tumbled, and as such, the lead (bullets) had darkened. I attribute that to the combination of NuFinish and mineral spirits I put in the treated walnut.

When I went to clean the gun a few hours ago, I clicked on my borelight and peered down the barrel.

Cleanest I'd ever seen that barrel after firing 100+ lead rounds.

Even more remarkable is the fact that these cast bullets I used were around 20 years old, and not of very good quality. We'd ordered from this caster back in my IPSC club days. He gave us a deal. We tried his bullets out and concluded they were average at best.

That's why I took the targets all the way back to 75 feet instead of the usual 50 feet--I was trying to really expose any flyers or deviation that might result between the tumbled and untumbled bullets.

But, no fouling whatsoever. I mean, NONE!

So NOW I'm doing a little thinking. Thinking I may try this thing (tumbling loaded rounds) with both my 45 ACP rounds (Mastercastbullets) and my 9mm cast bullets (can't remember where I got them--I usually load FMJs).

The experiment this time is going to be to see if they shoot any cleaner.

Hell, I may HAVE too much time on my hands . . .

Jeff

[Shane Tuttle]

Hell, I may HAVE too much time on my hands . . .

Well, I can use another member on my crew to get the maintenance done on our clients' planes...

[TexasSeaRay]

Well, I can use another member on my crew to get the maintenance done on our clients' planes...

Let's see. . .

I finish the annual on our plane Monday, plus change out both landing lights. Had to change a voltage regulator last week; she's due for a good wash and wax job--just waiting for the right weather day to happen on the same day I have a day off. Just did my 50-hour oil & filter change and sent samples off. GPS chip is due to be upgraded next month, and I have a new com antenna to install.

Damn things won't give you a moment's peace.

And now the wife's getting itchy about taking a trip somewhere--preferably where there's a coastline, and I'm still searching for a shooting range that has a landing strip on it or within walking distance.

THAT could make these experiments a little more efficient.

Jeff

[mniesen89]

when I trim my cases I am generally within .003 or so from one cse to the next.My question is, does being .003 off between cases effect accuracy and if not how far do you have to be off?

[Shane Tuttle]

And now the wife's getting itchy about taking a trip somewhere--preferably where there's a coastline, and I'm still searching for a shooting range that has a landing strip on it or within walking distance.
THAT could make these experiments a little more efficient.

Well, you're in luck!

My range is just down the road about 3/4 of a mile. Between it and my house is a gentleman with a private grass strip that's impeccably maintained. Our "coast line" runs between my house and work (Mississippi).

AND, since you know how to turn a wrench, you can help me finish up the following with no problem:

King Air F90
Complete Phase
6000 hr/cycle structural inspection
6000 hr/cycle cabin door insp
6yr/6000 cycle landing gear insp
6yr/6000 cycle landing gear motor o/h; gearbox insp
Double engine change/rigging
250 man/hours of structural repairs
470 man/hours of airframe/engine repairs

Grand total? 1300+ man/hours. HELP ME!!!

Bring your better half and I'll provide room/board/food/vehicle/tools.
You bring your guns and we'll split the ammo to go to the range on our "day" off and we'll experiment to your heart's desire...

[The Lovemaster]

TSR,

I tumble my loaded rounds for 15 minutes to remove lube. Your blackened lead bullets are caused by tumbling for long periods of time.

I also have the solution for your wanderlust. Fly over here to DVT and take me for a ride. I used to be a CFII, so I know my way around a Cessna. Then, we can cruise up the freeway to Ben Avery Shooting Facility, one of the largest in the world, and unload some ammo. To cap it off, we can go further west to Lake Pleasant, thus satisfying your wife's desire for a coastline. Granted, it's not saltwater, but we're waiting for the Big One in CA to create some Arizona coastline.

Scott

[TEDDY]

Gentlemen:this contriversy has been a farce for long time.the factories do it.I do it on rifle loads and on any rifle or pistol cartridge that has stains.the grains are coated with grafite to lube the powder.the grains are made of celulose.they dont crumble.the surplus cartridges get thrown around in cases
put on trucks on bumpy roads and sent on ships.think man think.just like measuring powder for every case,the factory does not.not that that shoudn't be done but for most shooting its not nessary. ---

[Fly320s]

If I ever find a shooting range that has its own landing strip, I'll be in real trouble.

A grass strip is a shooting range!

3,000 feet of grass is a 1,000 yard range. Just be mindful of the planes in the flare; they really mess up your group.

BTW, nice shootin'.

[Oz_Shadow]

I read elsewhere that swaged bullets do not hold up as well for tumbling.

[BIGR]

Makes for some real shiny rounds. Never tried to tumble any loaded ones.

[FM12]

All I'm going to say is: I'm going to find some links to help you work on your accuracy!

[Sport45]

Originally Posted by TSR

When I went to clean the gun a few hours ago, I clicked on my borelight and peered down the barrel.

Cleanest I'd ever seen that barrel after firing 100+ lead rounds.

I don't understand how tumbling loaded rounds could have any effect on leading. The part that comes in contact with the barrel is inside the case and not touched by the cleaning media, powder, or anything else.

[TexasSeaRay]

I don't understand how tumbling loaded rounds could have any effect on leading. The part that comes in contact with the barrel is inside the case and not touched by the cleaning media, powder, or anything else.

I don't either.

And it makes my head hurt to wonder too hard about it.

Jeff

[Wibb]

Looks like your lead oxidized during tumbling. Interesting experiment.

[Edward429451]

Nice shooting. Does one test make an accurate conclusion though? Maybe there was no difference in ammo accuracy, but you held better for the tumbled group? If you did this test 30 or 50 times I wonder if the results would differ and a clear pattern emerge?

[Bullet94]

I don’t tumble load cartridges and I’m not sure if it matters but after a quick search I found this -

Q. Is tumbling loaded ammunition dangerous?
A. Short term tumbling will have no real affect on loaded ammunition, but extensive tumbling can cause the breakdown of the powder grains. This would have two major effects. First, smaller grains will ignite more quickly than larger grains, and second the deterrent coating on the outside of the grains may be rubbed off and will be absent from any fractured edges which will cause the powder to burn more quickly raising pressures.
Tests run some years ago by a commercial entity did indicate that potentially dangerous changes in powder charge burning characteristics do take place after PROLONGED periods in either a vibratory or a tumbling cleaner.
The key word here is prolonged. Many manufacturers of ammunition do a final cleaning of their product either by tumbling or a vibratory process before boxing it for shipment. In no case is this allowed to exceed more than just a couple of minutes. The intent is not so much to "polish" but to remove any traces of contaminants which might in time leave marks on the finished product. There seems to be a consensus among the ammunition manufacturing engineers that a minute or two of vibratory cleaning has no discernable effect on burning rates, especially for loads that are compressed, or nearly so. However, all have emphasized the need for EXTREME CAUTION not to overdo the process.
They also pointed out that there is a considerable difference in effect on the powder charge depending on whether the process is by "tumbling" or "vibrating." It would appear that tumbling has less effect on the powder than vibrating, though this is mostly a matter of degree. The admonition to use EXTREME CAUTION to insure that the process never exceeds a couple of minutes applies equally to either process.
Ideally you should do your reloading after an extensive cleaning of the empty brass so any cleaning after loading is merely to remove traces of lube or to keep fingerprints from staining after a couple of months storage. A two stage process is recommended. One minute or so in a fairly abrasive cleaner with a tiny bit of solvent added to it to remove any traces of lube left on the brass, followed by one minute or so in clean corncob media to remove any traces of abrasive. Religiously follow several basic rules: use only a small amount of solvent and do the cleaning in a well ventilated area; change your media frequently, never letting it "load-up" with lube; and never "let it run while you do something else" and run the risk
of letting it run too long and altering the burning rate of the powder.

[Bruce Layne]

I did a similar experiment. I placed some ammo I had loaded into the tumbler with walnut media and took out ten rounds after 30 minutes, another 10 rounds after another 30 minutes, and so forth, up to an hour. I shot them in that order, so I should theoretically be able to detect a developing overpressure problem. I didn't see much difference in the ammo performance. I was shooting over a chrono, and any velocity differences were close to being statistically insignificant, although if memory serves the velocity did increase slightly with more tumbling.

I loaded 128 gr cast lead flat point 9mm bullets and I was probably using Hodgdon Universal powder.

WARNING: I wouldn't recommend this process to anyone even if they used the same reloading materials, and all bets are off if a different powder is used. I'd be concerned about all the issues mentioned in the previous post - smaller broken grains, burn rate modifier being scrubbed off the outside of the grains, and exposed fracture lines with no burn rate modifier at all. There might even be a problem with fine powder dust settling in the primer, perhaps converting it into a super magnum primer. I don't know if any of these issues are a problem, but they seem like legitimate concerns.

I also agree with the post that the exposed end of the lead bullet should have no influence over leading because that's determined by the shank of the bullet that's inside the case neck and thus not exposed to tumbling media. If there was less leading, it's probably because the lead hardened with age to the optimum hardness for the load you were shooting. The book Modern Reloading Second Edition by Richard Lee has an excellent description of lead hardness with respect to chamber pressure. Best accuracy and minimal leading usually occurs at a pressure slightly below the maximum pressure for that hardness. At that hardness, the lead flows (obturates) enough to seal the bore and prevent hot gases from leaking past the bullet and melting the lead (gas cutting). At higher pressures, the bullet is deformed from the pressure to the point that hot gases can again bypass the bullet.

My lead bullets were various shades of tan (30 minutes of tumbling) to gray (4 hours of tumbling). This isn't oxidized lead. It's just the fine dust from the walnut shell media mixed with the burned powder and primer residue and oxidized brass becoming embedded in the bullet lube or outer layer of lead. It was actually a benefit for me. I was using Lee Tumble Bullet Lube and it's sticky, even after all the solvent evaporates. I think it has a lot of low melting temperature bee's wax. The dust that was forced into the lube eliminated the stickiness while leaving the lube on the bullet shank where it's needed. I've read of others who sprinkle mica powder on their cast bullets for the same reason.

I don't really have any need to tumble my ammo for very long. I already tumbled the brass for four hours to clean it. For rifle ammo, I tumble the brass for 30 minutes after resizing to remove the resizing lube. I use full synthetic motor oil. Try it! You'll like it! I prefer to clean the sizing lube from the inside of the case for best consistency, so I tumble the brass before loading it. I very lightly lube straight wall pistol brass before loading it in the progressive press, but the carbide dies theoretically don't need any lube, so a couple of quick spritzes is all that's needed for 500 cases and I don't bother to remove it. I might be tempted to tumble that pistol ammo for 15 minutes, but otherwise I don't have a need to tumble loaded ammo.

I don't think the argument that manufacturers tumble loaded ammo is valid. They develop their load for their process. They may use a slower powder so after tumbling the burn rate is what they want. Our load data assumes that loaded ammo isn't tumbled. Apples & oranges.

If I had to guess I'd say that most of the time, tumbling loaded ammo won't cause an unsafe condition. It's the rest of the time that worries me.

When in doubt, I err on the cautious side. I plan on using up all my "stupid luck" at the range shooting propane cannisters and other juvenile stuff, not at the loading bench. YMMV.