"Halo 4: I Get a Woman!" - Sgt. Mjr. A.J. Johnson, RIP

[Champ]

http://www.youtube.com/watch?v=rIOOgFUwZfA
CTF footage. Apparently you automatically get an infinite-ammo pistol when you pick up the flag, but you can't drop the flag. Bizarre.

From reading the comments it looks like even if you have something other than the pistol as your second gun, you'll still have it when you pick up the flag. Also looks like you run at normal speed with the flag.