Heh, I made the mistake of sitting waiting for a pirate to make the first move after I was interdicted.
I saw what I thought was a pulse laser, turned out he had a single C2 Railgun on his sidey.
Two shots, and I was onto about 85% hull from a little under 1k range. Yes I kersploded him, but it was a painful game of waiting for him to gain a bounty for shooting me first! I need to start playing around with the comms - or getting a better look at their armament before engaging!
Dual Rails will still burn through you from a hidden, or devious foe. I'll wait until I see what's going on with Rails before I worry too much though (this chap was getting off 3 shots or more before it appeared he had coolant issues).