How to build Lego Revolutionary War Cannons - YouTube
LEGO Cannons Compared (Firing vs Non-Firing) - YouTube
LEGO Pearl Dark Gray Cannon (Shooting), 2x4 Red Cannon Base. 2533c01 2527 | eBay
I made a lego hand cannon when i was bored(you can reload like most of handcannons in destiny(if you want too see write in comment) and it shoots but not very well) :
LEGO MOC Compact Cannon with wheels by Xigphir | Rebrickable - Build with LEGO
Projectile Launcher, Cannon Shooting : Part 2533c01 | BrickLink
Cannon Power - LEGO Pirates - Eurobricks Forums
Amazon.com: Brick Loot Exclusive Pirates Cove with Cannon Gun Set - Toy Building Blocks 74 pcs Kit - Custom Designed Model - Compatible with Lego and Other Major Brick Brands : Toys & Games
LEGO Star Wars Death Star Cannon 75246 Multi 6251737 - Best Buy