Thanks.

You make it.

Keep in mind, the .50 Sniper Rifle you can craft from the base Hunting Rifle isn't necessarily the "best" Sniper Rifle in the game, if you're looking for a scoped, long-range murder machine. A Suppressed Gauss Rifle is probably your best bet, although a six-crank Laser Musket is also damn powerful (and has more common ammo) if you're not looking for sneak attack bonuses.

In my bag.

From a lucky drop by a legendary enemy:

Instigating Gauss Rifle, which you then fully mod.

(Or you could just use console commands to spawn a gauss rifle, and then add the instigating prefix to it).

you can also buy "the last minute" gauss rifle from Ronnie shaw at the castle 50% bonus limb damage

The arms dealing in diamond city (arturo) sells a unique laser pistol named "Old Faithful"

It's unique mod is that it does double damage to targets at full health, and sniping is generally all about those 1-hit kill shots from far away, right?

So get it (it costs somewhere around 2200 caps) and mod it with : Sniper barrel / Marksman's/recoil comp. stock / highest damage capacitor you can make / long scope (normal,nv or recon) and fine-tuned beam focuser to finish up.

Without loading my game back up to look, i'm doing somewhere around 110-125 dam as my base. Add in sneak attack bonus AND the unique mod for double-damage against full-hp target, and i should be able to 1-hit kill just about ANYthing i hit in the head*

*possibly exempting power armor / deathclaws / any other legendary enemy that spawns from a tougher-then-human base creature

Vault 81 - Overseers Guardian from Alexis Combes

Assuming that the bonus from old faithful stacks w/ the bonus you get for doing a sneak attack, i'd think that a properly max-mod'd OF like i described above would still out-damage that one. Maybe not by leaps and bounds, but enough to be counted the superior sniper. If the sneak bonus dosnt stack, i'd think that the 2 gun's performances would probably be about even, and it would just come down to your preference for sniping gun: energy or ballistic

I have yet to meet an enemy I could not oneshot with the instigating gauss rifle. (normal difficulty btw).

204 base from fully modded gauss rifle, x2 from maxed out rifleman, +15% from 3 ranks bloody mess, +5% from it being a scoped weapon, +5% at night, +50% maxed out mr sandman, x3.5 sneak attack from maxed out ninja, x2 against fully healthy target. As I'm not entirely sure how everything stacks/boosts eachother I have no idea what the final damage total is.

I don't recall: can you suppress the energy weapons? Don't think so but not sure....

Gauss rifle yes, laser rifle no, plasma rifle no, laser musket no

Using this too currently. Better than my .50 sniper rifle, sadly.

The .50 cal mod for the Hunting Rifle is frankly just sad. By the time you can craft it, you can get any number of other weapons (Overseer's Guardian, Old Faithful, even just a laser musket) and mod 'em up to be vastly more powerful. One of my few disappointments with the game.

Its a very good Weapon to Fight against the bulletsponge on Survival Mode. At the Moment i just use a 44er Revolver with Ironsight + Realistic Weapon Damage Mod from Nexus.

Old Faithful is a good long-range weapon for mid-game for sure, but since you can't silence it the Sandman bonuses don't apply. Since you CAN silence a Gauss rifle (though realistically you shouldn't be able to because of the sonic boom...) the max bonus is around 6x without an Instigating Legendary effect. My Prime character is using a Crippling one because it's the best she's found and can one-shot a Glowing Deathclaw.

This. Mod this gun into a sniper rifle.

Personally I much prefer a .308 chambered Combat Rifle with pretty much any legendary type.

You need to mod an existing legendary and take the right perks.
Various perks will give advantages for sneak attacks with a scoped, silenced, semi-automatic rifle.

I'm not keen on the Gauss, yes it has devastating first shot potential but a lot of that is wasted in overkill on regular mobs, against oversized opponents I'd much rather have the quick fire rate of the Combat rifle and its 40 round magazine.
.50 cal sniper is a real disappointment, magazine size and rate of fire limitations just don't compensate the small damage increase.
For a sniper style I always think energy guns kind of miss the point... just follow the big red line or series of green dots back to the sniper!!!

I love my two-shot .50 caliber sniper rifle. Damage is around 250 or so...... With just the base sneak attack modifier, it does pretty good.

Last Minute. modded out. getting 480+ !

done.

I believe the most powerful sniper rifle I found was a plasma rifle from a raider. It does 100 ballistic and 100 energy damage. Never used it though, I stuck it in a locker back at Sanctuary where I specifically store powerful weapons... Legendary weapons have their own lockers.

I prefer to use my trusty .308 recon combat sniper rifle which does 92 damage.

Seems like some of us are answering different questions.

The OP is "What is the absolute best sniper weapon?" That is the fully modified Instigating Gauss rifle. And secondly, "Where is it?" However, I don't think there is a scripted location which guarantees this. You have to wait for a fortunate Legendary drop.

Other good weapons are being listed, and preferences listed (and this kind of drift is natural for a forum thread, I know) but the "most powerful" is what it is.

I prefer my two-shot gauss rifle, while the double dam from instigating is very powerful for the first shot, it only gets its bonus for the first shot. Double dam once vs double damage all the time?

Unless I am totally wrong, is the the two-fer mod the best for projectile weapons in the game I wonder?

The gauss rifle is the best sniper rifle in terms of actual damage. It's really heavy though, and the ammo is much more scarce than most ammo types so it's not always the most practical weapon to use.

The hunting rifle can get fully modded into the .50 Recon Sniper Rifle, which is my favorite sniper rifle in the game. I scored an Instigating Hunting Rifle in a legendary drop, and fully modded it into an Instigating .50 Recon Sniper Rifle. Double damage when the enemy is at full health, which is the ideal perk for a sniper rifle.

The combat rifle can be modded into an excellent sniper rifle as well. The Overseer's Guardian is a legendary two shot combat rifle and is one of the most powerful guns in the game, especially after modding it with the .308 receiver. This is one of my other main guns, but personally I prefer to use it as my primary weapon, and it's geared out to be more of a short to mid-range weapon. I've got a reflex sight on it, rather than a scope. It can be a beast of a sniper rifle too, but it doesn't quite match the damage of the instigating .50 sniper rifle against an enemy with full health.

To each his own, but I find the imprecision of the two-shot irritating.

Also, if info posted here is to be believed, the two-shot is not double damage because the second "free" shot is the base unmodified damage, which can be significantly less than a full-boat modded shot. I can't personally confirm that, though - as I said, I don't use them.