Here are the ones I have gotten so far.
BULLETS:
D20
Snowballs
NUKES
Starter Bullets
Manip Bullets
Helpers
Fireballs
Ghost Bullets
Arrows
Darts
Bouncies
Shotgun Shells
Chaos Rounds
Sniper Rounds
Stock:
Drunken
Commando
Reversal
Void
The Underarm
Star
Sticky
Pistol
lovely
AK
Barrel:
Sniper
Sticky
Shotgun
Other shotgun (one that shoots 4 projectiles)
Stub
Bouncy
Pistol
Void
Drunken?
Laser Guided
Mo' Money
lovely
mini gat
AK
Mag:
Quicky
Canister
Re-loadable Canister
Double Smoker
Drum
lovely
spin
Trigger:
5x burst
double tap
bow
sticky
void
bouncy
Mo' Money
Grip:
Bouncy
Mo' Money
Rubber
star
Extended mag grip