MindsEye contains 11 campaign weapons. Finding all weapons unlocks the Sticks and Stones trophy & achievement. 10 of 11 weapons come as automatic story rewards and as drops from enemies. Every enemy you kill will drop their weapon.
You can mark nearby enemies by pressing D-Pad Down. Then simply run over their corpses to collect their weapon. Do this throughout the game and you will obtain all weapon types along the way.
The only weapon that doesn’t come from enemies or story rewards is the SGIAN-DUBH (Rocket Launcher). It can be collected in Mission 33: In Pursuit Of The Orb. Everything else you should get through natural gameplay.
This guide lists the first location where every weapon appears. However, the weapons frequently appear after that throughout the rest of the game. So if you missed a weapon at the first opportunity do not worry, keep playing and you will quite surely get it later on.
In case you are missing any weapon after the story, you can use Mission Replay to get what you still need. All your unlocked weapons carry over when replaying missions. Meaning, you can use endgame weapons in early game missions during replay.
You can view your weapons via the weapons wheel: Hold L1 on PlayStation / LB on Xbox. Some weapon types let you switch between 2 weapons. When you hover over the weapon it will have a white dot in the middle of the weapon wheel, then press D-Pad Left/Right to switch the sub-weapon. This is only the case for Pistols (top of weapon wheel), SMG (bottom), Energy Weapons (left bottom).
Weapon Locations
- Delta .45 (Pistol) – Mission 3: A Strange Happening – automatic story unlock, as soon as you enter the first fight.
- VT-9 (SMG) – Mission 6: Watch and Observe – dropped by enemies during this mission, after the driving section when you arrive at The Plains and have a shootout with enemies.
- Linebacker (Shotgun) – Mission 8: Robin Hood – dropped by enemies during this mission, in the trailer park, after the cutscene where the trailer explodes and you have a shootout with enemies. Some of them carry a shotgun. Also more enemies have this weapon later in the mission, after the car chase, when you’re in the shootout in the residential neighborhood.
- Wraith (Assault Rifle) – Mission 8: Robin Hood – dropped by enemies during this mission. In the trailer park, after the cutscene where the trailer explodes and you have a shootout with enemies, a guy shooting from a car will have this weapon. Also more enemies have this weapon later in the mission, after the car chase, when you’re in the shootout in the residential neighborhood. Particularly the enemies to the right of your car where you spawn when the shootout starts. Mark them all with
and walk over their corpses to find it. You can equip this weapon by hovering over the VT-9 SMG in weapon wheel and press 
/ 
. - DPR (Rifle) – Mission 8: Robin Hood – after the car chase, when you’re in the shootout in the residential neighborhood, the enemy shooting out of the car has this weapon. Alternatively, in Mission 9: Meeting Marco Silva – during the first shootout in this mission, one enemy drops it. The last enemy upstairs, before reaching the big drone that you have to chase.
- L-RAM 3000 (Sniper Rifle) – Mission 17: A New Job – automatic story pickup during this mission, can’t miss it. Picking up the Sniper Rifle is a mandatory main objective.
- FERRER-Y1 (Machine Gun) – Mission 24: Lights in the Sky – the first time you encounter an enemy with a Machine Gun is late into the objective “Follow Rigby’s Drone”. On the story path you come to a point where you walk across a pedestrian bridge while getting shot at by drones. After leaving the pedestrian bridge, in the next group of enemies one of them has the MG. Mark all enemies with and run over their corpses. You encounter the next machine gun enemy in Mission 25: Oh Lily!, while escaping the bunker an enemy shoots it at you from a staircase, you have to go up those stairs for the story path and walk into him automatically, would be hard to miss the weapon at that point.
- CARNYX (Laser Rifle) – Mission 25: Oh Lily! – during objective “Get to the Bunker”. After you arrive back at the Bunker area in the desert, you will be attacked by lots of enemies and robots. In the first group of enemies, one of the robots drops the Carnyx laser rifle. Mark all enemies with and run over their corpses. Alternatively, a little bit after this, Morris will call you and tells you that “the robots have laser weapons and they might be a good additional to your arsenal”, you can kill any of the remaining robots and get the weapon from them. Also more robots will have this weapon later so it’d be hard to miss.
- .50 SC (Handgun) – Mission 27: The Transponder – automatically picked up during this mission, when you open Silva’s safe for story purposes. Can’t miss it.
- SGIAN-DUBH (Rocket Launcher) – Mission 33: In Pursuit Of The Orb – found during objective “Find the Orb”. Unlike other weapons, this is neither dropped by enemies nor is it an automatic story unlock. If you’re missing a weapon it’s likely this one. During this mission you enter a military facility, your friend “Rigby” will drive a vehicle through a tunnel while you shoot a mounted machine gun. After the second driving section, you leave the car and continue on foot. Rigby will open a door while you defend her from more enemies that come through the tunnel. Afterward you go through a gate that Rigby opened for you, then you go further downstairs into the military facility. After going downstairs, there’s an orange-glowing weapon in a side room you pass by. You will walk right past it on the mandatory story path, but if you rush through it’s easy to overlook. When you scan with it will also be marked as an “ammo pickup”. Rigby will also say “That weapon, what is it?” when you walk past it on the story path. So if you just listen out for her dialogue you will know when you’re close.
- CLAYMORE (Energy Shotgun) – Mission 33: In Pursuit Of The Orb – found during objective “Find the Orb”. After collecting the SGIAN-DUBH weapon, continue until the next cutscene. After that cutscene a bipedal robot spawns right in front of you in the corridor that has this weapon. Basically unmissable because you have to walk through the narrow corridor where the robot is. More robots after this point will have the Claymore. You can select this weapon by hovering over the CARNYX in the weapon wheel and pressing / (it’s the second type of Energy weapon).
The Claymore is the final weapon in the game. If you found all other weapons, 
Sticks and Stones trophy/achievement will unlock immediately when picking up the Claymore. If you missed anything you can replay missions. The only one you might be missing is the SGIAN-DUBH, everything else is pretty much unmissable.
