Bullet life?

[hurrakane212]

How long do bullets "stay fresh"? I have heard of people saying they needed to shoot their ammo and buy more since their ammo was "old."
When is ammo "old?" Why does it get that way? ~Nathan

 

[JohnKSa]

If stored properly, rimfire is considered to stay good for at least 10 to 15 years if stored properly--centerfire indefinitely.

Properly is in a cool (comfortable temperatures), dry place.

Ammo doesn't really get old unless it's been abused. Temperature extremes can break down or alter the properties of the powder & primer and, of course, moisture causes corrosion.

 

[jondar]

While metal detecting in an old section of the city being cleared for urban renewal a friend of mine found a .38 S&W cartridge down about an inch. IIRC it had a headstamp of UMC or Rem-UMC. We wondered if it would fire. He had an S&W Victory model chambered for this caliber and we tried it. It fired and turned out to be black powder, judging from the cloud of white smoke.

 

[Backfired]

Bullets last forever

However, ammo does have a limited shelf life.

 

[EddieCoyle]

If stored improperly, rimfire ammo can have an exceptionally short lifespan. I bought a couple of bulk packs of .22 (Federal) ammo almost exactly a year ago when going shooting with a buddy. We shot all of one box and about half of the other box, this ammo worked fine. I gave him the rest of the 2nd box and he put it on the dashboard of his truck where it stayed, in the sun, until July.

When he tried to use it, he had two squibs in the first 4 tries. I tried some in a 617 and had a squib on the second round. We tossed the rest.

 

[Andrew S]

In my CCW class I learned its good to swap out your carry ammo a few times a year as a precaution. The ammo can be exposed to a lot of sweat and solvents if you shoot your carry piece with other ammo at the range and you clean it often. Our instructor said he does it every 6 months and he uses the time change as a reminder.

 

[rdbrowning]

"Bullet life? "
About the amount of time it takes to hit it's target.

The bullet's life before shooting is indefinate. The loaded cartridge can degrade if stored in either a hot or damp condition the powder can change it's burn rate. Hopefuly and usually downward. There have been cases where the burn rate has gone up forcing the chamber pressure too high. Also primers can degrade and not fire reliably. Thus the need to shoot "old" cartridges. Or at least that is the excuse I give my wife!