The only thin gI can say is don;'t try and be a sniper in a laggy game... people jump all over the map and you'll never get a shot off... as for leading, sniper bullets are instantly transported to the target.The newest strategy that I found to be both funny and effective is this:
This requires two people. One of them an APC driver, the other, an engineer/technition/hotwire ("unit").
Have the "unit" place remote C4's all over the front of the APC (only the front and ALL OVER... reload with the Purchase terminal and continue loading the fron t till you can't anymore)... if friendly fire is on.. expect your APC to die.
At this point RAM either a building or a vehicle you desperately need destroyed... call "DESTROY THAT VEHICLE!" and have the engineer detonate the mines... voila
If Friendly fire is off.... you can have multiple engineers detonate at different times so that it's not over kill.... otherwise KAMAKAZE!
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A variation of this strategy would be a solo mission where you put proximity mines ALL over your tank... looking for trouble 
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HAPPY HUNTING 