What you need: Primary weapon where you are close to earning a 10,000 XP bonus (500 kills, 250 headshots etc) Secondary weapon (Only tested on pistols so far) Slight of Hand Pro (May not be neccassary) What you need to do is to get the kill with your primary weapon and immediatly switch to your sidearm, before the 10,000 XP comes up on the screen. If you do it fast enough the XP will be added onto your secondary also [media] http://www.youtube.com/watch?v=9sak1QxJ9us [/media]
Been using this a while 2 things it may say ur getting 10k xp twice but it only gives it to you when u max out proficiency and also slight of hand pro is needed and only works with a pistol as secondary.
