[heypete]

Per the recommendation of people here and in other forums, I have picked up 500 rounds of Lake City 2004 vintage XM193 for defensive/SHTF rifle use. (For reference, the traditionally-overpriced local gunshop had 2,000 rounds in 500 round cases [1,500 now :)] for about $125. Damned good price, only about $20 more than mail-order.)

While the annealing stains around the necks of the rounds don't bother me much, there are some black flecks of stuff and other minor blemishes on the casings. As I'd like these to be 100% reliable in feeding and extraction, I'm contemplating tumbling the loaded rounds for about an hour.

Some people have said "NEVER TUMBLE LIVE AMMO! It breaks the powder down and hugely increases pressures!", while others have indicated they've tumbled live ammo and had no problems.

As this is almost-mil-spec (hence the "X" designator), I would imagine that the powder and other components are more than rugged enough to withstand high-vibration transport by aircraft or ground vehicle, variable temperatures, etc. I doubt that a mild tumbling would harm them, but figured I'd ask for a second opinion here.

[jobu07]

I've never heard of any serious malfunctions for doing so. No kabooms or such.

[cidirkona]

I wouldn't even bother, personally. It's not like they're going on display or anything...

-Colin

[ny32182]

First off... 2000 rounds of XM193 for $125 isn't just a good price... it is a *great, awesome, excellent* price, and if I were you, I would run, not walk, back to the gun shop and buy the rest of it up before someone else does. Mail order is MUCH more costly than that.

Second, I have a 500 round stash of the same ammo (I paid $110 in a shop locally for just the 500 rounds, and considered it a decent deal) for the same purpose. It has the same occasional black blobs of what looks like wax on it, but I would just pick those off as I loaded it in magazines... I don't see a reason to tumble them.

If it differs from the old mil-spec, I don't know how... I believe it is the exact same load that was military issue before M855 came out, and many people say it is more effective against unarmored targets than M855 (not as penetrative; easier fragmentation).

[AZ Jeff]

If it's just discoloration, and it's purely cosmetic, I would not both tumbling it.

If you MUST tumble it, I would not worry about breaking down the powder, provided you do some LIMITED tumbling. (An hour would be OK.)

Commercial ammo is usually tumbled after final assembly to do a final cleanup on it, so obviously, SOME tumbling with loaded powder is not deleterious to the performance of the ammo.

[heypete]

First off... 2000 rounds of XM193 for $125 isn't just a good price... it is a *great, awesome, excellent* price, and if I were you, I would run, not walk, back to the gun shop and buy the rest of it up before someone else does. Mail order is MUCH more costly than that.

It would seem that I didn't make myself clear (I do that a lot). It's $125/500rds, with a total of 2,000 rounds available. A fair price, but nothing special. Not a bad price at all for cash-n-carry, rather than waiting for shipping.

If it differs from the old mil-spec, I don't know how... I believe it is the exact same load that was military issue before M855 came out, and many people say it is more effective against unarmored targets than M855 (not as penetrative; easier fragmentation).

The "X" designator means that it didn't quite meet mil-spec M193, most notably in regards to primer sealing, which isn't a big deal to me. It is newly-manufactured on the same machines as military ammo, but this is just stuff from a lot they rejected (doesn't mean every round is bad, many shoot tons of "X" ammo without a problem, it just means the test rounds didn't quite meet spec).

I got the XM193 precisley because of the anti-personnel characteristics. XM855 would be nearly as effective, I would imagine, but supplies of it are not nearly as common, as its being used in prodigious quantities by front-line troops.

[taliv]

tumbling loaded ammo isn't bad for a few minutes, typically to remove case lube.

tumbling loaded ammo for "an hour" would be bad, IMHO. potentially galactically bad.

[dmftoy1]

You might do a search in the handloading forum. I asked this question a couple of months ago and got a ton of answers. There is a guy on there who seems to know his stuff and he did some experiements tumbling for VERY LONG extended times and then chrono'd the ammo and also pulled some bullets. The general consensus was that there is absolutely no problems with doing it.

Just my .02

Regards,
Dave

[rbernie]

tumbling loaded ammo for "an hour" would be bad, IMHO. potentially galactically bad.Why?

[swingset]

Tumbling live ammo doesn't hurt it, at all.

End of discussion.

[MAUSER88]

WRONG!!! Do not tumble live ammo. My shooting buddy tumbled 300 .223 reloads that he made. Same load he has locked into his Dillion machine for about 10 years of reloading. First round in his Remington 700 blows the floor plate open and locks the bolt. Damn lucky it wasn't more serious. Five minutes later he loads up his AR. First round blows the mag out and cracks the bolt. We both are totally stunned!
I ask if he did anything different in regards to reloading. Nothing he says, same load I'm been making for 10 years. Then he asks if tumbling the loaded cartridges over night could have anything to do with it as it he forgot to turn off the tumbler.I tell him no, I never heard of that before. He normally tumbles the live rounds for exactly one hour.

When we go home we, pull 5 loaded rounds and compare the powder to what's left in the can. The powder in the brass has turned to almost dust like particale's. Very different than what's left behind in the can. He spent the rest of the afternoon pulling the rest of the 300 loaded rounds.

Next weekend he loads up 10 rounds without changing any settings on his Dillion machine and fires them through his other AR. Fired and functioned perfectly.

Lesson learned, I wouldn't tumble more than an hour ever. Personally I don't tumble live rounds at all anymore. Two rifles blowing up in the same morning was enough for me.

[rbernie]

When we go home we, pull 5 loaded rounds and compare the powder to what's left in the can. The powder in the brass has turned to almost dust like particale's. Very different than what's left behind in the can. Out of curiosity - what powder?

[MAUSER88]

I believe it was IMR4898.

[wanderinwalker]

Mauser88, can I also ask what kind of tumbler and was it all 300 at once in the tumbleer?

I ask because I have tumbled about 120 or so loaded .223 rounds for 5-10 minutes in a standard vibratory tumbler (you know, the kind where the cases rotate up and down through the media). Never a problem, and this was match ammo loaded with Varget. The stuff will still clean targets all the way to 600 as long as I pay attention. Granted, I haven't loaded any on the progressive in a while; I just set up and take my time on the single stage right now as I am well caught up on supplies. Not only that, but I was/am incredibly careful to NOT leave the rounds on for more than 10-15 minutes at a time.

[MAUSER88]

He used a vibrating type tumbler and tumbled all at the same time. 10-or 15 minutes won't make any difference. You can always check the primer for any over pressure issues.

[chopinbloc]

don't bother, the ammunition is as close to 100% reliability as human beings can make it.
The "X" designator means that it didn't quite meet mil-spec M193, most notably in regards to primer sealing, which isn't a big deal to me.
i don't believe so. the x simply means it is designated for civilian sale. through some obscure regulation, manufacturers are not allowed to sell lots made for military use to civilians. the military still issues m193 ammo for training as it is cheaper than m855.
the stuff on the outside of the rounds does not matter a bit. the only reason to clean it up would be to make it prettier. military ammo is not highly polished for several obvious reasons. if you want pretty, shiny brass, buy civilian ammo, if you want good stuff that goes bang and hits the target, m193 is perfect. i tell you what, all the m193 i've ever been issued looks and shoots identically to the xm193.

[chopinbloc]

oh, yeah, you mentioned shtf ammo. do you really want to leave a trail of nice, shiny brass for the enemy to follow if you find yourself in a jeffersonian episode?

[AZ Jeff]

For all of you who insist that tumbling loaded ammo will break down the powder, and result in catastrophically higher burn rates, I have two questions I would like you to answer:

1. how do the commercial manufacturers get that finely polished finish on the loaded rounds they package? (After all, the machines for stuffing the bullets into the cases WILL leave marks on the brass. How do they remove those marks?) ANSWER HINT--it's via tumbling.

2. once the loaded rounds are packed into their cartons, how do the manufacturers avoid powder disintegration during the transport vibration that is seen when the ammo is trucked from the factory to the distributor, and from the distributor to the dealer? (transportation vibration is NOT insignificant. I have been involved in subjecting products to transportation vibration testing for 25+ years, and it CAN take it's toll on stuff.) ANSWER HINT--the ammo is subjected to MUCH vibration in transit.

If you can explain to me how these two types of vibration are avoided, then perhaps your claims of vibration altering the powder burn rates will make sense. Otherwise, it's an old wives' tale.

[MAUSER88]

If you think loaded rounds bouncing around in a truck for delivery is the same as being in a vibrating tumbler for 9 hours, your sadly mistaken. :banghead:

[AZ Jeff]

If you think loaded rounds bouncing around in a truck for delivery is the same as being in a vibrating tumbler for 9 hours, your sadly mistaken.

Do you have any experience in performing or witnessing transportation shipping tests? I do. You might be surprised how MUCH vibration (and how LONG) such tests call for.

For example, imagine the vibration experienced during a cross-country road trip via truck.