Here, have a couple lists:
Vanilla weapons NERFED by Calamity:
Daedalus Stormbow - 25% base damage reduction
Razorpine - 5% base damage reduction
Phoenix Blaster - 25% base damage reduction but made autofire to compensate
Venus Magnum - 25% base damage reduction but made autofire to compensate
Blizzard Staff - 25% base damage reduction but reduced mana cost by 2
Last Prism - 15% base damage reduction
Vanilla weapons BUFFED by Calamity:
Beam Sword - Made autoswing
Magic Dagger - Made autoswing
True Excalibur - Made autoswing
Book of Skulls - Reduced mana cost by 6
Frost Staff - Reduced mana cost by 5
Unholy Trident - Reduced mana cost by 11
Magnet Sphere - 10% base damage increase
Frostbrand - 10% base damage increase
Tome of Infinite Wisdom - 20% base damage increase and reduced mana cost by 10
Gungnir - 20% base damage increase
Poison Staff - 20% base damage increase
Flower of Frost - 20% base damage increase
Chain Guillotines - 20% base damage increase
Stake Launcher - 25% base damage increase
Muramasa - 25% base damage increase
Vampire Knives - 33% base damage increase
The Rotted Fork - 33% base damage increase
Phasesabers - 33% base damage increase
Amber Staff - 33% base damage increase
Excalibur - 33% base damage increase
Nettle Burst - 33% base damage increase
Charged Blaster Cannon - 33% base damage increase
Clinger Staff - 33% base damage increase
Life Drain - 33% base damage increase
Crystal Vile Shard - 33% base damage increase
Paladin's Hammer - 50% base damage increase and made autoswing
Pulse Bow - 50% base damage increase
Keybrand - 50% base damage increase
Wasp Gun - 50% base damage increase
Lunar Portal Staff - 50% base damage increase
Flamethrower - 50% base damage increase
Elf Melter - 50% base damage increase
Night's Edge - 50% base damage increase and made autoswing
Venom Staff - 66% base damage increase
Inferno Fork - 66% base damage increase
Sleepy Octopod - 66% base damage increase and made autoswing
Christmas Tree Sword - 66% base damage increase
Staff of Earth - 66% base damage increase
Medusa Head - 66% base damage increase
Wand of Sparking - 66% base damage increase
True Night's Edge - 66% base damage increase and made autoswing
Terra Blade - 66% base damage increase
Celebration - 100% base damage increase
Proximity Mine Launcher - 100% base damage increase
Ghastly Glaive - 100% base damage increase and made autoswing
Spectre Staff - 100% base damage increase
Breaker Blade - 100% base damage increase
Golem Fist - 100% base damage increase
KO Cannon - 100% base damage increase
Anchor - 100% base damage increase
Flower Pow - 100% base damage increase
Dao of Pow - 100% base damage increase
Sunfury - 100% base damage increase
Blue Moon - 100% base damage increase
The Meatball - 100% base damage increase
Ball O' Hurt - 100% base damage increase
Psycho Knife - 300% base damage increase
If any of you think we only nerf vanilla weapons then you are so out-of-touch with reality it hurts.
If you would like to know where I got this info there is a useful place called the Calamity Wiki:
https://calamitymod.gamepedia.com/Vanilla_changes
I only provide this information to stop the ignorance as it's getting really old