RE: Dented Ammo
I'd agree with Tree climer,
set the shell aside & contact Remington, much cheaper than an injury.
Some of the other that have responded, that talk about fireforming and oil/lube denting. Have a point, if you have a modern bolt action gun and your reloading. But if you have a factory cartridge and shooting a lever action gun (most 30-30s are). You have 2 factors working against you. 1. With factory ammo you don't know what the pressure maybe. 2. Lever action guns have a relativly weak lock up, & action.
There are a couple of good ways to dispose of a live cartridge, 1. Have someone that reloads pull the bullet out, then the powder can be dumped out. 2. Soak the cartridge in oil.
Good Luck