Here is the step by step instructions of making paper gun from Step 26.
Step 26: You should fold the paper as shown below.
Step 27: Similarly fold the other side of the grip. It should appear as we have shown in the below image.
Step 28: Pin each folded portion separately.
Step 29: Now your stapler should be as below.
Step 30: Draw three triangle markings on the barrel portion of the gun.
Step 31: Stapler the muzzle end.
Step 32: Cut the paper along the triangle markings.
Step 33: Once after cutting the triangle portion, the gun should look as below.
Step 34: Use a nylon rubber band and join the muzzle end with the triangle cuttings.
Step 35: Join two more nylon bands on the other two triangle cuts along with the muzzle end.
Step 36: Trigger the gun. You have shot a blast now.
Step 37: You have done your simple paper gun now.