For the bombas, don't sustain fire on them, just fire a regular shot or two and they should drop to the ground. You'll then have a few seconds to run to it and press B to kick it.
Also, just earned 'Proven Grounds', Challenge Pack 3 is a total pain in the ass but doable. Perserverance is the key!
100K Score Achieved on 14th March 2012, Mass Effect 3 "Well Connected".
Last edited by JohnnyRock84; 08-19-2009 at 06:23 PM.