From October 26th to November 2nd, Double Experience will be live in Caliber. On these days, for each round, checkpoint, or milestone taken in Clearing, Showdown, Special Operation, Frontline, and Onslaught, will receive double the amount of experience. In addition, for the duration of the event, double experience is credited to the account as well.
Nothing complicated: you play for the same time and upgrade twice as fast. The promotion will run until the start of maintenance on Wednesday, November 2nd.
The amount of experience during the event is shown in the pics.
XP amount during the event in Onslaught
XP amount during the event in Onslaught: Halloween mode.