Step 1 - Start with a square on the right side of the page and add another rectangle on the left side half the height of the square.
Step 2 - Add one vertical line inside the square's left side and two horizontal lines, draw another rectangle on the right side of the square a little bit shorter.
Step 3 - Draw the grip of the gun, start with a curved line and connect it to the back part of the gun, now add the grip shape attached to it.
Step 4 - Sketch two oval shapes for the gun's trigger, a bigger and a smaller one inside, add a curved line inside the smaller oval.
Step 5 - Draw half a circle in the middle of the gun, on the back part add two horizontal lines and connect them with a diagonal line.
Step 6 - Keep adding more details to the back part of the gun and add the gun's hammer using half a circle and a smaller circle inside.
Step 7 - Add more details to the front part of the gun using two horizontal lines, two rounded shapes at the bottom and a curved line for the muzzle.
Step 8 - Sketch more details on the gun's grip, start with the magazine shape at the bottom, add a curved line for the back part and another zigzag line where the fingers should come.
Step 9 - Draw the gun's barrel with three vertical lines and two rectangles on the right side.
Step 10 - If you were drawing with a pencil, you can now trace your guidelines with a black pen and erase the pencil lines after. You can also print this image of Nerf Gun Coloring Page.
Step 11 - Now all that's left is to color your drawing, enjoy :)