Here is my choice.
It is my .54 Hawken copy made by Doc brown of Everson Wa.
My load is 80 grains of 2 F , a .15 patch and a .530 round ball.
That's plenty good for soda cans , or just about anything else , LOL
Andy
but for kids, fill the empties up with water and set something on top. Then it becomes a contest to see who can launch what is sitting on top the highest.