There are quite a few choices where I don't really agree and some, namely the KO-Cannon and the Anchor, where I really can't even imagine the reasoning behind the rank.
Speaking of which: You might want to give some reasoning for your choices as well, so people understand the advantages and disadvantages of the weapon and your thought process more easily.
Anchor: Easy to get maybe, but that doesn't help if the weapon is pretty much entirely useless with its measly 30 damage. How this is supposed to be B-Rank is beyond me. I'd go as far as giving this weapon its own F-Rank for completely useless items. Why? Remember this weapon comes from Wooden Crates opened in hardmode, but while you open those, you will likely get hardmode ores or even bars if you have fished up some Iron/Gold/Biome Crates while you were fishing for Wooden ones.
If you ask me, this weapon is bad enough for me to think that it was originally intended to be available pre-HM, but the devs accidentally made it HM-only. It's nothing more than an improved Harpoon, but I wouldn't even use it in late pre-HM. The only HM weapon that I can think of that is even less useful is the Pearlwood Sword.
KO-Cannon: A-? Seriously? Please explain how in the world is this weapon good at all? Pretty pathetic damage output, no multi-hit ability and a whopping 0.1% drop chance during a Blood Moon. Keep in mind that you want to farm this with pre-HM gear for it to be of any use at all. You're going to spend hours on end to even get it, because Blood Moons only happen with a ~1/10 chance and you can't kill enemies all to quickly with your pre-HM equipment. I don't like flails personally, but I'd rather get myself a Dao of Pow, which deals 18 more damage, multi-hits, has more knockback and takes less time to get. The KO-Cannon is a clear D-Rank in my books.
Death Sickle: I understand it's a good weapon, but you need to take into account that it's extremely rare for anyone to obtain before you get Solar Tablets in the Temple. Without the tablets, Solar Eclipses have a 1/25 chance of occuring on any day, meaning an average player spends 10 hours waiting for one to occur randomly. You also likely need several Eclipses to happen to even get a single one of them, so an average of 10 hours of waiting usually don't even cut it.
If you progressed post-Plantera, though, its usefulness is pretty much limited to its ability to attack through walls, whereas its damage is severely outshined by the Terra Blade.
A-Rank is okay, but it's not powerful enough to constitute an S-Rank if you ask me.
Fetid Baghnakhs: This weapon is in an extreme niche, since its miniscule range prevents it from really being all that useful in most scenarios. Using it against bosses isn't really much of an option, since you'd need to literally facetank the boss for that to work. It's not awful, but clearly not an A--Rank in my books. I'd say B, because it sports very high damage with very limited usability, which is not unsimilar to the Daedalus Stormbow.
Hallowed Repeater and Titanium Repeater are almost identical apart from the Hallowed one dealing 2 more damage, but you put the Hallowed in C+ while the Titanium is D. Hallowed requires you to kill a mechanical boss before you can get one, making it harder to get in comparison. I'd put both of them at C-Rank.
Shotgun: It's a decently useful allrounder for the ranger and probably the easiest one to obtain out of all the weapons listed here, since you just need 25 gold and an Arms Dealer. It's in a similar category as the Clockwork Assault Rifle, sporting less accuracy and DPS in return for quite decent knockback. Also keep in mind that the Shotgun can also get the Unreal modifier, while the CAR can only get Demonic at best because it has no knockback. I'd put it into B-Rank.
Breaker Blade: This weapon's usefulness is severely limited by the alternate options you very quickly have. You might as well stick to the Night's Edge or get yourself one of the HM-ore swords. Using it instead of the Night's Edge is more of a style choice than an upgrade of any sort.
I'd put this into C-Rank.
Phasesaber: This weapon is obtainable at about the same point you can get a Mithril/Orichalcum Sword, since you need the Mithril/Orichalcum Anvil for it. It is roughly as good as the Mithril Sword and worse than the Orichalcum Sword, so how can it be B-Rank while those two are C-/D-Rank?
Whether you change anything is up to you of course, but I think I gave decent reasons for my choices here.
