No Explosives Airsoft Grenade

a lot of people like you like airsoft (if you dont why are you reading this) but who has access to C4 and TNT so

you will need alka seltzer water a film canister and some BB's 

this is pretty simple load the bb's into a film can with some water add an alka seltzer put the cap on and throw it.
the cap will blow of letting the bb's blast out of the hole flying at your opponent
i know this doesn't have great distance but it is a good distraction to snipers and people coming towards so you can shoot them