The Sporting Carbine is a primary weapon that can be used ingame.
It can be picked up, or if you have the correct perk activated, it can be started with as well during campaigns and other modes.
Due to the semi-auto, its fire rate is lower but at the max upgrade level it is able to penetrate multiple zombies at a time, and coupled with the high accuracy makes for an all around amazing weapon.
The magazine's max ammo capacity per magazine is 30 rounds, with an extra 180 in reserve. The base weapon with no upgrades only sports 20 rounds.
It shines in sniper scenarios where you want to move silently (Provided you have a silencer) and overall helps greatly in mini hordes. In larger hordes however, you'd be better off using something else.