You get four different weapons in Tomb Raider and each can be upgraded by finding various parts throughout the game. This upgrades make the game much easier and let you buy additional perks for your guns. With this guide you will get them as you go!
If you miss a part you can always go back after you progress in the story via the camp sites. I am also starting to think based off all the comments that they are actually randomly placed on the island and based off how you far you are in the story and not a specific location. This is where I found my parts but most of them were in breakable crates so be sure to check crates as you progress!
You get an upgraded bow as you play through the story.
Bow Part 1
As you progress through the story you will eventually face off with a mini boss with a large shield, and you will have to kill him. The key is to wait until he attacks the use the dodge button to avoid him, after he misses shoot him until he dies. Once he is down loot his body for the weapon part.
Bow Part 2
After you call for the plane and it crashes, you will back track to the mountain village. Once there, you will have to wait for these three guards to separate while you are going to save the co pilot. Once they split up wait for the third one to take the rope down then take out the other two guards, break the crate on the ground near the steps to the house for the next part.
Bow Part 3 – Chasm Monastery
In the room where you need to open two windows in order to knock the bell from the ceiling, you will face off with a large enemy with a spear. Once you kill him loot his body and he will have the next bow part.
Hand gun Parts
You will receive a Handgun upgrade as you progress through the story.
Handgun Part 1
Completing the Hall of Ascension tomb will unlock this weapon part, check out our guide here Tomb Guide
Handgun Part 2
Beating the Chamber of Judgement tomb will get you this part, the guide is here Tomb Guide
Handgun Part 3
Beating the Temple of the Handmaidens will get you the last pistol part, check this guide Tomb Guide
Rifle Part 1
Right after the Hall of Ascension tomb you will make a rope bridge down to another platform. Look right and you will see another platform you can jump to, on that platform is a crate that has the rifle part in it.
Rifle Part 2 – Shanty Town
After you make it through the water part and back to land, you will face off with some pirates. Take the stairs up and loot all the bodies to find the next rifle part.
Rifle Part 3 – Shanty town
As you progress through the story you will come to part with people throwing dynamite at you and sounding an alarm. You will have to face a few waves of people and after you kill them you can cross the gap, once across drop down and break the crate to get the part.
Shotgun Part 1 – Mountain Village
After you hear Sam get taken over the radio you will need to work your way back down the mountain. On your way down you will be to the back of 4 guys grabbing some fuel and talking about it being pay dirt. Kill them and one of them has the shotgun part.
Shotgun Part 2 – Solarii Fortress
After you find Sam and attempt to escape with her you are ambushed in a burning building. Kill all the enemies until two big units arrive, kill them and loot both of them for the shotgun part.
Shotgun Part 3 – Cliffside Bunker
This is the area of shipwreck beach where you find some guys welding equipment and chatting while you sneak in. Kill all the individuals in the room until you are allowed to go up to the second floor, there will be more enemies up there so kill them as well. You should see a gap with a door on the other side, jump the gap and open the door to gain access to the shotgun part in a crate.
I’ll be searching for the rest of the parts after I finish up the guide, check back soon for updates.