Think it depends more on your passive ability cards and getting thouse that matter to lv3, and ammo selection, then what kind of weapons you bring.
If you are looking at 1 shot capabilitys, the shotgun is your go to, buckshots kills anything up clouse while slug kills anything at mid range, quick aimfokus too.
For long range you are going for headshots anyways so quick aimfokus repeaters, like the lancaster works nicely. Dual handguns i think is better for pvp, then pve. You want to pop headshots on the AI and to do that you need to ADS.