The nail bomb is a crafted proximity mine made from a blade and an explosive. Bill gives Joel his first one inside St. Paul's church in Bill's Town, and after that you can craft your own.
Bill rigs Lincoln with tripwired nail bombs and the hunters do the same in Pittsburgh, so watch the ground for wires. Place your own at a doorway, then make noise to pull enemies onto it. On a burning bloater, a nail bomb deals a lot of extra damage.
Pump shotgun
The pump shotgun is Joel's close-range long gun, handed to him by Bill in the cellar of his church during Bill's Town. It kills most humans and infected in one blast up close, but loses power fast with distance and reloads one shell at a time.
Baseball bat
The baseball bat is a blunt weapon that swings faster than the pipe or 2x4 and lasts six hits. The first one sits on top of a washing machine in the laundromat in Bill's Town.
Bow
The bow is the quiet long gun. Joel finds it at an abandoned camp in Lincoln during Bill's Town, and its arrows can often be pulled back out of bodies, which makes it a stealth tool and an ammo saver.