Don't know if its under the rules, but lego Nerf Rapidstrike CS-18 : r/legoguns
تويتر \ Patrick Chovanec on Twitter: "My 10-year old son used Lego to design a flashlight attachment to his Nerf Gun. It ingeniously uses a rubber band to create the friction needed
Working LEGO Nerf Gun - TUTORIAL - YouTube
Lego Nerf gun - The Brothers Brick | The Brothers Brick
LEGO blasters in a Nerf Battle? No Thanks! | Blaster Hub
Nerf, or rather, Lego Super Soaker Water Guns : r/lego