I didn't play Clam Blitz since it came out until just recently. How do you carry this mode? Normally if you're stuck in a low rank you just go to the objective and kill everyone, but people are all spread out in this mode and low ranks are too uncoordinated for teamwork to really work.
I found that inkbrush was my saving grace for low rank Clam Blitz. Simply rush the power clam to the basket. Trash level players can't take you down easily. It absolutely does not work at higher ranks, though.