noun
Refers to a complete round of ammunition for a firearm, including the bullet, casing, powder, and primer.
猟銃に弾薬筒を装填する。
Load a cartridge into the hunting rifle.
実包 is a synonym for 'cartridge' but is less common in everyday language; 弾薬筒 is more technical.
Compound of 弾薬 (ammunition) and 筒 (cylinder/tube), literally 'ammunition cylinder'.