Halo: Combat Evolved included a feature called "weapon launching" that allowed you to use the blast from a carefully thrown grenade to cause a weapon to fly towards you. With a bit of practice, and a knowledge of where to stand and look before throwing the grenade, it's possible to collect weapons from across the map.
Here's an example from Combat Evolved:
Weapon launching is back in5, and you can see some examples of the practice in the video at the top of this story. You'll even earn the "Combat Evolved" medal for pulling this move off successfully, just in case you're wondering if this was a deliberate throwback to the classic days of the franchise.
It's an interesting gambit to bring back to the game, and it's going to be fun to see what competitive players are able to do with this trick as the beta continues.