I'm actually a little confused about the description of the heavy flamer. It fires backpack-mounted canisters. But it does not say if the canister IS the backpack (in which case the HF would have 10 shots period, and "reloading" would be replacing the entire backpack). Or if the canisters are separate (albeit large) "clips" that are inserted into the backpack, in which case it could be reloaded by taking a canister and inserting it.
For that matter, how much ammo does the heavy gunner get for his weapons? The launcher gets 4 missiles obviously. Does the hevay stubber get a number of "clips" (ammo drums, I suppose)? Does the heavy flamer just get the aforementioned backpack, or a number of canisters?