That is certainly more creative that what we did when I was a kid at about 12 years old. - We had two crazy ideas that were more dangerous than we realized later. Definitely not as sophisticated the machete shooter.
The first was to get a regular sling shot with a leather projectile patch. We substituted it with single rubber bands grouped together. For ammo, we cut 1" or so pieces of solid copper wire and crimped them with a pliers into a "vee" shape.. - Not very accurate, but it got a squirrel if you could ever hit it. It was more fun to shoot at a big piece of cardboard with a target to measure accuracy. We got smart and put a piece of sheet metal behind the target, so we did not have to make many more wire "staples" since they went through and got collected below the plate.
Our major triumph was a really big slingshot. We got a large tree branch the a "vee" in it. We found one about 10' or 12' long and about 4" or more diameter at the base. It was really heavy. We went through the scrap pile at a local plant and found some very stretchy tan rubber bands. We put them together in two long sections and attached to a piece of an inner tube to put rocks into. We went to a sand and gravel pit and put it into a hole in the ground and shout the rock that was there at the "cliff" to make it fall in and down. It took about 8 or 12 to hold it in the hole and brace it while got a few more to pull it back and let it fly. The rocks we shot were about 6" to 8" across and then we would go out and get more rocks and shoot another round.
It was a lot of fun for week-end.
I have no idea what good it did for us later in life but I know that two became engineers, two ended up being English or history teachers and a couple became priests or ministers.
Good old memories of being a kid.
Dick