Depends a lot on connection. Good connection can make it blow up when ever you want, normal connection makes you wait the first half second or so. Also, as you're throwing the bombs(from my experience) it has a wider radius in the air as it does on the ground. Sometimes the second the bomb hits the ground, the radius is it shows is smaller than the actual radius it blows up. #TheMNCStruggle
you need to look up and jump as you toss the bomb to get the most range from it. If not be higher then the person you are tossing it to and look downwards. With the right timing and angle and knowabouts where players camp or sit you can toss bombs and knocked them out of areas they camp. (steel peel bridge by top spawn) Almost everyone camps there with ice traps, firebases, bombs. General rule is look up there jump and toss then detonate while it goes over the top of the corner. Mash the button as quickly as you can to compensate the lag. If your on host your bombs will go off perfectly in the air with minimal effort and your assault rifle will have auto aim and your bullets will connect. Basically if you play cod enough and know how to toss c4s over walls etc then youll be a pro with the assault bombs. Its almost the same idea. Bangathon used to be one of the best bomb tossers in the game then the last patch crippled how the bomb reacts due to people crying for a patch. Its sad how the brats who whined and complained about the game left this game and the forum so long ago and we are stuck with a somewhat unbalanced mess to some extent. The host priviledges pretty much ruin the game for the other players.
That is pretty much it though. You throw the bomb and you get used to throwing it after playing more and more. Sometimes you get fucked from lag not letting you blow it up like scratchy said but for the most part it is just experience.
muscle memory and prediction. you played quake right? they're like rockets. don't throw them where you see the enemy, but anticipate their movement and lead them. Play solo and just throw bombs from down low into various areas so you have an idea of how much you need to look up.
you want to get good with bombs? Have the enemy team spawn buzzers and try to kill them with your bombs.