Hi, I saw this contest super late(just around 5 hours ago), but I did my best to give you an excellent design. If I got more time I could give you more designs also upgrade the ones I sent. Details of designs: -Hexagon Design: ths design have 8 rectagunlar shape holes(4 in 45 degree and 4 in 135 degree), these holes have the function of relieving air pressure to improve recoil and also that the weapon does not have as much force upwards, pushing it down with the air pressure. -Cilinder Design: the same idea as the above, but in a different shape. -The last design I was lacking of time, my original idea was to look alike a sharp. The upper triangular shape have the function of redirecting the air to push foward the gun. So you will have less recoil on your shoulder, body.