What weapon do you like to give your careful shooters?

[Jake]

I'm going to go assault an enemy base for the first time ever.  In light of that, do the suggestions stay the same?  I have no idea what base assault is like.

For picking off hostiles from outside, yes, though I'd also take at least one LMG along as a turret substitute. If you plan on going in and clearing the place out room by room, not so much; the survival rifle's rate of fire is too low for CQB. Assault rifles, machine pistols and/or heavy SMGs are ideal for that, pump shotguns or pistols should work if they're all you've got.