I saw a guy on youtube who's sniper does about 1500 dmg, plus the legendary perk of doing double damage to enemies with full health. I can't remember what his level was but I'm pretty sure he had all the rifle associated perks maxed out.
wtf
Gauss rifle is probably the heaviest hitter in the game
weapon perk (200%) + bloody mess (115%) + lone wander (130%), and I think I have some other damage perks (maybe megazine).
you can easily break 1k damage if I am not mistaken
actually i maybe mistaken with another weapon
i am not at home right now but i just checked my old video https://www.youtube.com/watch?v=2N4omu7a2_g&feature=youtu.be
i haven't take lone wander rank 3 yet but it already got 463 damage. if I am not mistaken I think i got some legendary weapon later in the game but i forgot what, have been switched to big gun for a while.
with lone wander I think damage is about 600, if having something like 2 shots legendary or +25 damage legendary it should be easy to reach 1k.
There is one Guass call "The Last Minute" that can be buy after the end of one faction and that one have higher base damage than normal Gauss i think. beside that one... you probably need to go hunt legendary
okay used console to done some testing
for max damage (with all perks beside megazine and companions)
* 579 - full upgrade
* 661 - +25% damage legendary effect
* 911 - Two shot legendary effect
The Last Minute have same base damage as normal Gauss so Wikia info is incorrect again
Edit: Updated damage that is using rank 10 megazine
okay data updated. i think 911 maybe the highest possible. if i didn't miss anything. consider combine with sneak attack and other thing u can probably break 5k damage in one shot
The gauss is by far the strongest in terms of single shot damage if all effects are equal. That said, you don't need the gauss to utterly decimate everything in survival difficulty... you can easily kill anything in the game long before it can reach you with other weapons.
If you take the Rifleman, sandman, and ninja perks and get rifles with the "2 shot" perk, you can 1 shot almost anything in the game with a sneak attack with any rifle higher than a .38 caliber. If you postition well, you can get several sneak attacks on a target before "Caution" turns into "Danger" and you are considered to be in combat. This is especially true if you have the "sniper" perk that knocks targets down, because knocking a target down will delay their ability to force you into combat. For this reason, I'd say that the Overseer's Guardian is one of the best, if not the best weapon in the game. (Cheap and available ammo, great dps, great range, effective against all targets, great magazine size, great optics)
A 2 shot assault rifle would be marginally better than Overseer's, but the Overseer's has a fixed location where it can be bought, making it readily available to any player provided that they haven't turned the vendor hostile against them (or killed the vendor).
But the highest possible damage weapons in the game are 2 shot gauss rifles and 2 shot fat mans in terms of paper doll single shot damage.
In terms of raw DPS (on a zero armor target), I believe that an explosive minigun can deal the most raw dps. Granted that this doesn't mean much since a sneak attack with a rifle is going to deal more burst damage and the 5mm round doesn't have anywhere near the armor penetration that the heavier rounds have and also will have a much lower accuracy and effective range.