The phrase "extra ammunition" refers to additional bullets or firearms that someone carries with them, usually for use in a dangerous or challenging situation. Full definition
However, many owners feel better knowing they are providing their dog with a little bit of extra ammunition to help the immune system do its job. (petwave.com)
The equipment section lets you get nice perks such as extra ammunition, or adrenaline. (pocketfullofapps.com)
You can buy extra ammunition, and more supply crates. (goodereader.com)