‘MURRICA

can-berra

65% KClO4

35% dark aluminum Powder

Compress some in a PVC tube, close ends with toilet paper and hot glue with a long fuse and have fun.

Should be all available online.

Alternative if you can't get KClO4:

replace KClO4 with KNO3 (Stump remover for example) and add 10% sulphur to enhance criticality