This is an awesome collection of guns that I use in my Lego models and I've never seen them used anywhere else so I thought I would share them. Hope you enjoy :) I have the instructions for most of them but the variants and the sword based guns are easily copyable from a picture.
Step 1: Pieces
Sorry for the bad quality, my camera wouldn't zoom. These are the pieces you are going to need for every gun so if you have all of these ready then you'll be able to make all of them.
Step 2: Simple Shotgun
First you attach a pair of binoculars to the gun base. Then you add the connector pieces.
Step 3: Other Shotguns
These are some other cool variants of the shotgun...
Step 4: Cool Machine Gun and Chainsaw Attachment
They go well with mainly Star Wars Lego but does fit in with other sci-fi Lego. on picture 4 the first gun is finished so I take it out.
Step 5: Epic Sniper?
I don't really know what to cool this one but it sure is SUPER EPIC!!!
Step 6: Sword Based Guns
These two guns don't require many pieces or rare pieces. For the instrux of the second gun I used the wrong gun piece but I corrected myself in the last picture of the sword/gun.
Step 7: Dwarven Hammer
This is from a LEGO Hobbit set and I thought that you may not have the set so you wouldn't have known what it looked like. Well done LEGO for this amazing hammer design.