The M7 is a .22 bolt-action rifle and one of the first guns you pick up. You cannot buy it, only find it. Damage and accuracy are low, but .22 ammo is everywhere.
It fills the primary slot early when you have nothing else. Use it for headshots on Swarmers and lone humans.
The .22 Repeater fires faster and can be bought and stored. Either should give way to the M14 or an automatic rifle as soon as possible.
.22 Repeater
The .22 Repeater is a Poor-condition primary rifle you unlock at Tucker's Hot Springs camp. It fires fast and its ammo is everywhere, but each shot hits soft. Use it for early Swarmer packs, then replace it.
Badlands Big Game
The Badlands Big Game is a Special Forces lever-action rifle for the primary slot. It reloads slowly, but every shot is accurate and heavy. It is a strong pick if you like to fight humans and big Freakers from range.
IDF Pup
The IDF Pup is a Special Forces bullpup rifle you get free for clearing Hordes. It unlocks at 50% of Horde Killer with a 45-round magazine. It is accurate, fast and one of the best primaries for Horde fights.
M14
The M14 is an Average-condition semi-automatic rifle sold at Lost Lake from Trust level 1. It fires quickly and accurately, which makes it good for picking off targets at a distance. An extended magazine takes it from 10 to 16 rounds.