Here's a pro tip from top 10er (yes I'm giving away all our secrets): Even if you are out of ammo (or just finished a 3 round pack), move forward and trigger PvP again. If it's a Point boost, bonus! If it's not, you just wait 10 minutes, let your energy and ammo regen, and then try again. Keep triggering pvp until you either get a point boost or your ammo is full and you have to spend it. Don't waste your 12+ streak battles on non-point boosted matches unless you absolutely have to.