Slinghshots are powerful weapons. But there is a limit to their destructional capabilities, as the speed of rubber is limited - and so is the speed of the ammo. One can use heavier ammo to achieve more energy. But there is a limit to that, too - if the ammo gets too big, it won't penetrate, just smash. Heavy ammo is expensive, too.
A big steel ball like the 20 mm (.79") is pretty much the maximum size ammo that makes sense. The ones used in this video will crash though wooden boards, watermelons, even coconuts. But imagine what a simultaneous impact of six of them can cause!
The Slingshot Channel presents "The Avalaunche" - the first slingshot crossbow that shoots six rounds at the same time. One trigger pull and all six are on their way to the target.
The weapon is big and has an enormous draw length. This means the six balls hit with about 60 Joules each. Enough power to demolish several objects! As always the video contains slow motions recorded at 40x realtime (1200 fps).