I haven't tried it but the only thing i can think is that in this circumstance you're "wasting" the huge slot on a large weapon.
Have you tried something like... Huge Cannon, 2 med Pulse and 2 med MC's? The pulses can be on one fire group, and then when shields drop you can switch to a 2nd fire group that has e.g. Mc's on primary and Cannon on secondary. Alternatively you could use a Plasma accelerator since its the single highest damage weapon you've got out there BUT of course its fixed not gimballed.... (and a HELL of a lot more expensive!)
Saying that, I don't think you'd struggle with the above set up. My vulture had no issue stripping shields off Anacondas in CZ's on my vulture and i was running 1 Pulse 1 Cannon set ups. Saying that If you have a good enough power distributor i think you'd be able to strip those shields just as easily with 2 constantly firing med pulses.