Mini Tnt Cannon

This is how you make a mini tnt cannon

Build a u shape and then add a slab at the top

And the water at the bottom of the u

Put the button at the bottom of the u and do the outside of the u with Redstone and then Add repeaters one block before the top block

Put tnt on the slab and the block next to it in the water flow

The tnt should go flying and blow up