Ex-Nasa engineer creates world's largest Nerf gun, watch as it fires giant foam bullets at 40mph

Nerf guns have changed a lot over the years, with most now resembling day-glo versions of automatic military-grade assault rifles rather than the single-shot pistols of the early 90s. But no foam-bullet-blaster can possibly compare to the new king of the playground – a whopping weapon that will make your Nerf war enemies cower in fear.

You can see the enormous pistol/bazooka-hybrid in action below, as its madcap creators blast apart a pane of glass, decimate a beautifully arranged plastic-cup tower and annihilate a family of innocent watermelons.

The gigantic gun is the brainchild of former Nasa engineer Mark Rober and a pair of engineers from the YouTube channel Eclectical Engineering. The trio split apart the gun to reveal how exactly they supersized a Nerf shooter and managed to make it actually work.

A 3000psi paintball tank fitted inside the grip compartment funnels pressure into an air tank. When the absurdly large trigger is pulled, the air is released, causing an equally huge bullet to take flight.

Not content with creating traditional suckered ammo - constructed from swimming pool noodles and the end of a toilet plunger – the team also craft a 3D printed missile. Thanks to its aerodynamic design, the latter manages to travel an incredible distance of 118m, which just about spans the entirety of an American Football field.

With the 'scientific' tests out of the way, Rober does what any man would do with such an absurd creation – terrify his unsuspecting children with it. A second video (below) starring the big blaster features the aforementioned horrors of the watermelon massacre. It is not for the faint-hearted. Those poor, poor fruits.