Rubberband guns (RBGs); the epitome of improvised weapons, carbine or garand, pistol or rifle. so many options lie with this weapon, but unfortunately people here are obsessed with K'NEX (personally I hate it, it has a high tendency of falling apart and breaking). so i will teach you how to make a RBG out of wood or metal (whichever is readily available).
I will use the example of a crucifix shaped gun called the punisher. It is weilded by Nicholas D. Wolfwood in the 1998 anime hit Trigun.
Step 1: Front Nook
Every good rubberband gun needs two places to hold the rubber band. this end will permanently* define the calibre (caliber if youre american) it should be at the end of your wood (pic 1) or halfway through (pic 2).
"slingshot" style sticks may be put there if you want raised firing arcs.
*open to interpretation, the trigger also defines the caliber too.
Step 2: Trigger Mechanism
now for the hardest part. there are two ways to do this: Carbine or Garand (and yes that is based directly on M1 styles). garands can go only 1 shot at a time, carbines have the ability to do several semi auto style but its far harder to make (better to buy one on E-bay or something).
ther design plan for a garand is below. it's exaggerated to fit my crucifix. you must create a hole for it to fit in. if possible cross-section it, put it together, then put the side back on.
Step 3: Optional: Sand and Whittle It Down.
as far as i've gone, all wve made is a block of wood that flings RB at high velicity. you might want ot sand it down and cut it so it looks like your favourite gun.
It didnt apply to me; all i needed to do was nail in another block of wood .!