Looking for a Summer Project? Try a Giant Nerf Gun.

Sometimes playing with your kids means suffering a little boredom for the sake of their happiness.

(Or at least that’s how I recently ended up spending an entire afternoon making hopelessly drippy sandcastles when all I wanted was some shuteye under the sun; small price to pay to keep them relatively quiet.)

But for ex-NASA engineer Mark Rober, recreation with his nieces and nephews has a bit of more, shall we say, edge to it. That’s because he and two of his engineering buddies just took it upon themselves to design and build the world’s largest Nerf gun.

This ain’t the air missile of your childhood. It uses a pressurized paintball tank to fire the ammo of your choosing — whatever that may entail — at 40 mph, good for a max target range of about 130 yards.

And the designs are ready to be put to use via a Youtube video the engineers made, including some modifications that will equip the gun to decimate watermelons.

Might want to put the kids to bed for that part.