[Theohazard]

1: Kept in a clean, dry place and at a constant temperature, ammo can last for generations. Ammo subjected to moisture (carry ammo, ammo kept in places with a fluctuating temperature) doesn't last as long. But you usually should be able to see any signs of corrosion: check for any "fuzziness" or discoloration, especially around the primer and where the bullet seats into the case.

Usually people replace carry ammo because the rounds have been chambered and unchambered so many times that the ammo is scratched and some of the bullets have been pushed back into the case. This is called "bullet setback" and it's dangerous to fire these rounds. Luckily it's easy to see when this happens.

The rule of thumb for ammo is that you can usually tell if it's past its prime just by looking at it. When in doubt, throw it out.


2: "Grains" refers to the bullet weight, not the amount of powder. Those rounds use 50 grain bullets, which is less than half the standard weight of most 9mm bullets. I'm not specifically familiar with Liberty Ultra Defense, but it looks like they're another one of those super-fast, super-lightweight, frangible-bullet designs.

There's a couple of problems with those. First, the bullet is often made from a pressed-together materiel so it will fragment in soft tissue or through walls. But this materiel is also usually much more susceptible to moisture: I had a friend who carried some RCBD ammo for about a year and when he went to shoot it his gun blew up after four rounds. It turned out that moisture had infiltrated the case and caused the kaboom.

The other problem is that the bullet often performs unreliably through heavy clothing and is much more easily deflected by bone and such. I'm sure there are times when a super-fast, super-lightweight, frangible 9mm bullet outperforms a more traditional hollow point, but this performance tends to be less reliable. There's a reason why almost all federal and state law enforcement agencies use more traditional hollow points.