Ammo in a truck for a long time?

[mongo]

Being the old fart that I am, I hear, and tell, a lot of stories... Well, here goes: Boxes of rifle ammo are left behind the seat of a pickup and forgotten about. Years and 50,000 miles pass and the ammo is found again. It is still looks clean and new, but when placed in a rifle and fired,signs of verry high pressure happen (hard to eject and flattened primers). Did the vibration and time of being in the truck cause the powder to break itself into smaller pieces and cause high pressures.....What says you all, true or bull???

[hotpig27]

I sold my 93 Cherokee a while back. it had 234k on it and lived out at the family farm in the weather. When cleaning it out I found all kind of ammo from 22 up to 308 some had to been in there ten years. I also found a Brolin Arms 1911 that I forgot that I had. I think they went out of business back in the 90's.

All of the ammo so far has fired without any problems or signs of over pressure.

[dk99358]

I think it would depend on the load density. If there is enough room for the powder to shift around, then yeah, I can see it breaking down and or the deterrent coatings being rubbed off. Either one will change the burn rate.

A load with no extra room shouldn't have this issue.

My $.02,

Dale

[Remington788]

This sounds like a job for


(Seriously, they are always begging for new ideas)

[notenoughguns]

I would say that extreme temperature swings degraded the powder more than the vibration , which would be little in the cab of a truck .

[Pa.Bill]

Reloads of .270 Winchester, 100gr. The box marked 3300fps.
They had fallen behind the bench, in an unfinished basement, back in 1985.
I fired a few last year- no problems at all.
I have no idea why that happened to you, but as long
as no one was hurt, all is well.

~BEST~

[dk99358]

"Old" is not the problem, it's the storage conditions. Vibrations, heat etc. I fired some 32 Spl this year that's been stored in the house since before 1974, no problems and the chronograph said the velocity was right where the factory said it should be. The OP's ammo has been bouncing around in a truck enduring less than ideal conditions. Big difference.

Dale

[West Chester]

Here is someone who did an experiment tumbling live ammo with up to 75 magnification looking at the powder.


http://www.ar15.com/forums/t_1_5/989...nds_in_OP.html

[tabasco_joe]

Vibration over a long time can break the powder down to smaller particles which can increase the burn rate thus raising pressures. Also some powder is coated to control burn rate and that can get ground off. Happens much more with rifle cartridges than pistol or shotgun.

This was more common back in the 50s and 60s with police out west where a box or two of 30-30s were in the car for years and then someone fired it. Used to be articles about it back the.

[West Chester]

Vibration over a long time can break the powder down to smaller particles which can increase the burn rate thus raising pressures. Also some powder is coating to control burn rate and that can get ground off. Happens much more with rifle cartridges than pistol or shotgun.

This was more common back in the 50s and 60s with police out west where a box or two of 30-30s were in the car for years and then someone fired it. Used to be articles about it back the.

The test above that I linked to really proves you wrong. He used before and after microscope pictures of different powders being in a case tumbler for 205 hours. There is no change in the powder as can be seen at 150x magnification.