If you don't know what semi-automatic means, it's single shot with a clip. Not hunting rifle, it'd be more like the Sniper Rifle, This Machine, Service Rifle.
Which one of these has the highest DT? Because I gave Arcade Gannon an AER14 (first playthrough that I EVER got a companion) and he totally wrecks everyone and now I feel inadequate.
DT? Don't you mean damage per shot or damage per second?
The Survivalists rifle from HH never let me down although the All-American has a good scope, larger clip size and more common/cheap ammo but has a lower dam:shot and DPS.
I would recommend one of those. Christine's COS silencer rifle from OWB has a better dam:shot but is by no means an all-rounder of a gun.