Theres some spoilers to the entire game.
 
Thats it.
 
Thats literally the note.
 
 

Crowbar

Near route kanal where barney gives you the weapon.
 
If you played HL1 then you’ll know its also the 1st item you get in the game too.
 
 
 

0. Energy Gravity Manipulator (Gravity Gun)

Can be found in Black Mesa East where Alyx gives you the Gravity Gun.
 
 
 

9mm Pistol

If you stab a CP unit with a crowbar. they drop a pistol.
 
 
 

357 Magnum

Found in Water Hazard when you go in an industrial (i think) place. you’ll spot the 357 Magnum on a table. along with it’s ammo.
 
 
 

SMG

The same with the 9mm pistol section, but this time they drop an SMG.
 
 
 

Shotgun

Found in Ravenholm where father grigori throws you the Shotgun.
 
 
 

Crossbow

Found in Highway 17 where you go to disable the forcefield on the bridge. (said by my mind when i was under the bridge)
 
Under the bridge you’ll see a dead refugee/citizen, Beside that theres a crossbow.
 
Aaaand you got it.
 
 
 

Pulse Rifle

Found at the end of Ravenholm if you go in a container and break a crate or kill a combine. (The combine elite too. they always use it.)
 
 
 

Grenades

Like the 357 magnum, but not in the same map.
 
In water hazard you’ll see a blocked off gate.
 
And in the gate control part of Water Hazard, you’ll notice of course, grenades, but in an ammo box. (green boxes with ammo sign on it)
 
 
 

RPG

In Highway 17, you’ll come across New Little Odessa.
 
In the basement of NLO, you’ll come across a meeting (or something), and Odessa Cubbage gives you the RPG.
 
And you take the gunship down.
 
 
 

Bugbait

In Sandtraps, you get in a fight with an antlion guardian.
 
After the fight you get greeted by a vortigaunt,
 
With the vortigaunt’s magic you get the bugbaits and get trained on what they’re for.
 
 
 

0. Energy Gun

In Our Benefactors, you’ll be dropped into a room where all your items get vaporized, but not your gravity gun.
 
This can be useful to beat the game later.
 
 

 
 
Hope you enjoy the Guide about Half-Life 2 – Weapon Locations in Game, if you think we should add extra information or forget something, please let us know via comment below, and we will do our best to fix or update as soon as possible!