AT4 Spring-Loaded Rocket Launcher | Print-in-Place

Want a scale model of the AT4 Rocket Launcher that fires little rounds over 14ft/4m?  This is completely print-in-place, just take it right off the printer and its ready to fire.  In my testing it routinely sent the bullet/round over 14ft/4m, but I'm sure you can make it go even further.  This print even includes a tank target to shoot at that falls over when hit. How do you shoot it?  Simply insert a round/bullet into the front, then pull back on the plunger at the other end.  Then rel