At 70 pounds fueled and pressure loaded with a 9 to 11 second time of fuel expenditure, not too good.
However, if you have a 12-gauge shotgun, loading the first round with a magnesium flake *dragon's breath* load can be effective and a whole lot lighter. It can be twice as effective in a double-barreled gun, particularly at night when bears often hunt by sense of smell, nearly as good as that of a dog.
The recoil of such loads is surprisingly mild, even in short-barreled *shockwave* guns, 12 gauge pistols and AOW weapons, and allows for a quick followup shot with slug or buckshot wait a repeater- and even a single or double-barreled gun can be recharged pretty quickly.
