Chronograph results from tumbling loaded rounds.

[Exposure]

Like many I have been curious if tumbling loaded rounds had any impact on the powder.

Last night I decided to do a bit of experimenting.

I loaded 20 rounds of .45 ACP. I then tumbled 10 of them for 15 minutes and left the other 10 just as they came off the press.

Recipe was as follows:

200 Grain Rainier plated RN bullets
Wolf LP primers
6.8 Grains Ramshot True Blue Powder
Once fired cases from many different manufacturers

These were intentionally light loads. But the results were interesting.

All 20 rounds were fired from a 5" barreled 1911.


Rounds tumbled after being loaded:

770.4 FPS

Rounds not tumbled after being loaded:

768.2 FPS

I would say that is close enough to be negligible.

The only difference was that the tumbled rounds sure did look pretty!

I know this isn't very scientific but for me it shows that at least a 15 minute post loading tumble doesn't hurt anything.

 

[ants]

It depends upon the standard deviations.

You can easily make it scientific. What were the standard deviations? You can calculate a comparison between two samples by using the mean and standard deviation. Do a little search on statistics, and do the math for us.

 

[mongoose33]

It doesn't really depend on the standard deviations. Those are close enough not to matter.

His samples are very small.

And unless he has remarkable consistency in velocities, he won't reach statistical significance.

Even if he did (and I'll bet you $100 he won't), what would that tell you? That one is only very slightly different? Not much value there.

 

[1SOW]

With a larger test base, simply measuring OALs might also be interesting.

I know the press will give several thousanths variation, but with larger numbers the OP's chrono results might have indicated an average two thousandth's/or more set-back.

 

[Ol` Joe]

He likely got no more tumbling done to the cartridges then they would see during transportation to and from his range and hunting ground from 15 minutes of cleaning.

 

[suemarkp]

Would suggest a repeat, preferably with a larger sample size (but 50 rounds total may still be enough). I'd also tumble way longer. If you tumble for 24 hrs and you still see no significant difference, then perhaps we can call the myth busted.

 

[Roccobro]

That has already been done. But the question still pops up every couple of weeks.

Justin

 

[depoloni]

I think the issue at hand is whether tumbling live ammo long enough to get it clean is detrimental to performance, assuming it's not CRUDDY.

I can't imagine that anyone would argue against the traditional warning about tumbling when you're talking about long periods in the tumbler. Take it 24 hours, or some other version of "indefinitely" and there's simply no way and no doubt there would be some degradation of the powder and thus it's behavior/performance. But within reason, I don't think it matters. The comments about transportation vibrations (and etc) over time are valid, 15 minutes in the tumbler won't be much worse if any than the amount of rattling that factory ammo goes through on its way to your door. Like anything though, take that simulation to the extreme with a day or two in a tumbler and you could and should expect different results.

Sort of where a grain of common sense comes in, pushing things is never the best idea - in reloading in particular.

 

[delta53]

The powder

coarseness may have a factor the more course the powder the more friction there would be and that would breakdown the size of the powder affecting burn speed

 

[Ret.CWO]

I can only say that I have tumbled/vibrated loaded cases for many years and never seen a difference in accuracy or performance. Never performed any kind of test. I would rather shoot clean cases than dirty stained brass. I guess it really wouldn't make a differance one way or another. I just like to make them pretty.

 

[snuffy]

I can't imagine that anyone would argue against the traditional warning about tumbling when you're talking about long periods in the tumbler. Take it 24 hours, or some other version of "indefinitely" and there's simply no way and no doubt there would be some degradation of the powder and thus it's behavior/performance.

This thread is in response to an earlier thread here;

http://www.thehighroad.org/showthread.php?t=495611

Powder does NOT "break down". Nor is the retardant coating worn off. It's old wives tales, internet myth and flat out lies! Most powder is coated with graphite, a natural friction eliminator. The powder itself is a tough substance, not easily broken or abraded.

the traditional warning about tumbling

Which "traditional warning" might that be?

I may do another test, just for more fuel for arguments like this. 50 rounds of 40 S&W, 25 tumbled for 24 hours, the other 25 shot without tumbling. 4.5 WW-231, 165 west coast plated, speer cases, ww SP primers. Shot over my pact chronograph at targets @ 25 yds.

Any other ideas as to powder type? I could do Unique, 700-X, blu-dot, power pistol, SR 4756,

 

[Walkalong]

I was thinking the same thing snuffy. W-231 would be a good one since so many folks use it. I was thinking about tumbling them for two days though.

I'll do the .45, if you do the .40. If you do W-231, I'll do another powder. Which one would you suggest. I have 700X, a flake powder, or I could do N320, a stick powder vs the flattened ball powder W-231. AC

 

[rcmodel]

24 hours!
You guys are gonna shoot your eye out!!

Seriously, I doubt you will be able to measure any differance atall outside normal SD for that number of rounds.

rc

 

[Walkalong]

I doubt you will be able to measure any differance atall outside normal SD for that number of rounds.

Yep. I have no doubt.

 

[Walkalong]

So what's it going to be, flake (700X), or stick. (N320)

 

[snuffy]

Walkalong, I vote for the 700-X. If ANY powder might break up, it would be a thinner flake. Also, IIRC 700-X is a single base powder, where Unique would be a double base.

I already had some loaded, but not with the west coast/extreme bullets. I used the berry's 165 plated for my last run through the 650. I just put them in, I'll go 48 hours also.

 

[Roccobro]

When I get my chrono, I'll do a test where I tumble for 7 days.

My poor tumbler... But my head hurts every time I see one of these threads pop up and ignorance starts seeping in... better my tumbler than my head!

Justin

 

[Walkalong]

OK. 700X it is. I need to load em up and get them tumbling. Results later this week. AC

 

[Kernel]

This is a cool thread. Though my wife ain't THAT old, I’ve always been of the “don’t tumble loaded ammo” crowd. I can see the advantages of tumbling, though. I’d do it in a minute, if it was shown to have no appreciable affect.

Trail Boss would be a good powder to test. Nothing is fluffier, and it looks rather frail and friable.

 

[Walkalong]

After the games (How about those Vikings & Jets!), dinner, and company, I set out to load 50 rounds.

I picked out 50 Winchester brass from some lightly tumbled range brass in the shed.

I set up the press and found a setting for 5.1 Grs of 700X on the Redding 10X. (21.9) As usual 700X metered so so. I loaded up some X-Treme 225 Gr TrFPs @ 1.215 O.A.L. using WLP primers seated with my RCBS hand primer.

I put 25 in the tumbler at around 9:19 PM Sunday night. I'll take them out Wednesday around 9:00 PM.

AC

 

[Walkalong]

Trail Boss would be a good powder to test.

Volunteering?

 

[Roccobro]

That's what I heard too!

Justin

 

[1SOW]

Easy for me to say, but measuring the oals before shooting might show some differences.

 

[kelbro]

Personally, I would be more concerned about wearing my tumbler motor out from the extra weight than the powder breaking down.

 

[CZ223]

If nothing goes BANG

You guys will at least have proven that it is not dangerous. That is what a lot of people have been concerned about, myself included. This is an interesting thread though and I am curious to see if you notice any significant differences in velocity. Okay, so which one of you guys is gonna wear the funny little beret'?