Deadshot, Bullseye and Wesley Gibson vs Batman, Batgirl and Daredevil
All have standard equipment. Bullseye has an M60 and a deck of playing cards to boot. Batman gets five minutes to prep, but no one else does. Which side wins?
Why do people think they are doing Bullseye a favor by giving him playing cards? Yeah he CAN kill with them, but its hardly a weapon of choice against anyone near his level.
In 5 minutes Batman could probably put on some comic-strength kevlar that seems to stop all bullets regardless of caliber. Still you are right, they can put enough lead in the air to arguably take out DD and Batgirl.
And I think they would dodge Wesley's gunfire after they disposed of the other two villains. Batgirl can straight outrun them, and DD can use use billyclub to knock them back in a rapidfire motion.
A bullet from Gibson's gun doesn't travel faster than any other gun. Batgirl has dodged 15 people pointing guns at her point blank in a small room, and her body reading would let her know what everyone's move would be before they made it.
Daredevil can sense the bullets trajectory know matter where it goes, and Batgirl has dodged bullets casually when she was even trying. She also has sonics and gas pellets.
You have someone with perfect vision firing 10 rounds a second, with the bullets travelling at 800+ m/s (SO SAYS THE ALL POWERFUL WIKI)
So if everyone starts at 0.5 km, they have dozens of perfect shots bullets at them from Bullseye alone inthe first 3 seconds, let alone Wesley and Deadshot...