When wandering the aisles of your local toy store, it's pretty easy to write Nerf guns and blasters off as just toys for kids. When you take one apart, however, you realise how much engineering has gone into shooting foam bullets. Let an engineer explain.
The new NERF Elite blaster is shaped like a modern Derringer pistol. It has a tri-barrel design, and requires the user to prime it by pulling down on a spring-loaded plunger to fire.
The interesting thing about this blaster is that it only fires one foam projectile at a time, despite using a single-plunger design to prime it.
A teardown reveals a nifty design in the tri-barrel that restricts the flow of air to barrels without bullets thanks to an O-ring. When the barrel is loaded, a tiny spring attached to the O-ring channels the air flow into the first loaded chamber for maximum bullet thrust.
Of course, the system can be fooled, and O-rings can be left slightly open to make all three bullets fire at once, but otherwise, it's an ingenious little system inside what is essentially a kid's toy.