Well, true story.
We used them on our radar sites because many are accessed via a runway. We had BASH training to haze wildlife in case it threatened a (military) landing. In one case there was an inbound C-130 and a moose on the runway. This was at Sparrevohn. My friend shot a bird bomb up into the air and arced it over. They don't really have much weight so they don't go very far, like a shuttlecock in badminton, and they are horribly inconsistent to include sometimes blowing up just feet away from the barrel. This one came down right along side the moose's ass when it exploded. It blew chucks of hair off his ass. It screamed and went running off down the hill then proceeded to keep running over the next two hills. It was funny shit and a lucky shot.
They are also waterproof for the most part. I like to shoot them underwater or into snow berms and blow them up.
In reality these days all firecrackers are limited to 30 milligrams of powder no matter how big or the shape and sometimes they pack multiple firecrackers into one big body. I think the bird bombs have more powder. But real M-80's had 2-½ to 3 GRAMS of powder. You could blow toilets off the wall with them.
The really cool bird bombs had to be the 37mm bird bombs but those got banned for sale after 9/11. You can get hollow rounds you can load up yourself though.
Oddly enough, you can still buy all sorts of exotic 12g ammo, many of them being the same as fireworks, or rounds like the bolo round with 2 slugs connected by 6" of piano wire, flechette rounds, dragon breath, etc.