Which weapon can firing those "Heavy projectiles"?

I make a lot canister weapon like, “Big Bang” “inferno” “blast” canisters, but I don’t know which weapon have those ammo types called “Heavy projectiles”, I can even craft a canister rack for that, but still don’t know which weapon with it.

The heavy projectiles are ammo for the slingshot cannon from blazemod.

Right, right. They’re kinda useless, though. Compared to other guns.

Yeah, the canisters are kinda useless unless you plan on bombing fungal infestations or something. But the slingshot cannon is pretty good before you get laser turrets if you load it up with rocks.