All credit for this guide goes to SnowNinjaRaccoon (DK) & PowerPyx from PowerPyx.com who provide a complete guide to finding all collectibles and all weapons in Vampyr.
This guide covers all 12 one-handed and 8 two-handed in chapter order, although the guide they created also covers all collectibles and ranged weapons as well.
Prologue:[One Hand Weapon #1] Used Machete
You will run past it at the very beginning of the game. You will have to pick it up in order to protect yourself.
Chapter 1:[Two Hand Weapon #1] Used Scythe
After passing the hideout on the higher floor you will cross a bridge and enter a tunnel. Jonathan will mention fresh blood. A bit further down the tunnel, you will find the scythe.
[One Hand Weapon #2] Used Bludgeon
Granted for Defeating William Bishop.
[One Hand Weapon #3] Used Hacksaw
Hospital, 2nd floor.
Chapter 2:[Two Hand Weapon #2] Common Barbed Cudgel
Found at the start of the Sewer Section (you go there during the story).
[One Hand Weapon #4] Used Hatchet
Whitechapel District, Northwest, Second Floor of the Warehouse with a Sewer Monster in it.
Chapter 3:[Two Hand Weapon #3] Common Mace
Hideout in Sewers (area where you meet Bridget).
Chapter 4:[One Hand Weapon #5] Remarkable Saber
Granted for defeating Doris Fletcher.
Chapter 5:[Two Hand Weapon #4] Common Axe
Found at the end of the sewers section with the Leon Augustin Boss Fight. After the part where you use the 3 valves to raise/lower the water. After lowering the water and making it to the other side there’s a bridge you can teleport up to (there’s a lady held hostage in the tunnels here called “Louise Teasdale”). It’s just before the sewer exit.
Chapter 6: Important: Make a manual Save Game Backup at the start of Chapter 6! See spoiler:
*** Spoiler - click to reveal ***Many weapons are from embracing different citizens so if you’re on your Pacifist run for trophy “Not even once” it is important you keep a backup save from before embracing anyone (killing people also voids side quests)!!!
After beating Chapter 6 there’s no way to go back (you would have to start a new game and lose all your progress). The Harriet Boss Fight is the point of no return, when this fight triggers is the last chance to go back. In Chapter 6 you can still free-roam and revisit places.
PS4 Backup: Go to PS4 Settings > Application Saved Data Management > Saved Data in System Storage > Copy to USB Storage (if you back up to PS+ Cloud be sure to disable Auto-Upload or else it will overwrite your save).
Xbox One Backup: Quit the game at the start of Chapter 6 to trigger the automatic cloud upload > (double-check that it really uploaded to the cloud) > go offline (pull the cable or disconnect from internet in console settings) > kill everyone for their collectibles > delete your local gamesave > go online again to automatically re-download your cloud-save and continue with the other path normally.
[One Hand Weapon #6] True Dragonbane: This weapon has it's own guide and achievement associated with it and is likely the most difficult item to unlock in the entire game:
[One Hand Weapon #7] Clay’s Hatchet
Kill Clay at the hospital.
[One Hand Weapon #8] Rakesh’s Surgical Saw
Embrace Rakesh in Hospital and loot his chest.
[One Hand Weapon #9] Newton’s Saber
Embrace Newton in Hospital.
[One Hand Weapon #10] Seymour’s Bludgeon
Embrace Seymour in the Docks.
[One Hand Weapon #11] Louise’s Machete
Embrace Louise in West End.
[One Hand Weapon #12] Archer’s Hatchet
Get it from Archer in the Docks.
[Two Hand Weapon #5] Joe’s Barbed Cudgel
Embrace Joe Peterson in Whitechapel and open a chest in Harry Peterson’s House (2nd Floor).
[Two Hand Weapon #6] Booth’s Axe
Embrace Booth in the Docks.
[Two Hand Weapon #7] Rodney’s Scythe
Embrace Rodney in the Sewers (Docks Event on a map).
[Two Hand Weapon #8] Samuel Connor’s Mace
Kill Tippets in Hospital, Loot Tippets, Loot his Desk/Drawer/Locker (don’t remember which one it was) in Doctor’s Room in Hospital. With the small key head to the basement of the morgue where a corpse lies on the table. Loot the chest there for the weapon.