Having flown with these new armoured doors I am positive that it would take more than just 30 seconds to break through one unless you were armed with some 'plastique' and knew where to place it. However, there are serious security flaws in with the system which I won't go into detail on here but suffice it to say that the classic opportunity to rush the flight deck will still be during feeding/watering time for the pilots.
Now, I'm just playing devils advocate here as I don't hold a definite opinion one way or another whether pilots should be armed or not but, for all those gung-ho, pro-arming pilot types out there, the most likely scenario I can envisage is the well trained terrorist making a grab for a cabin crew member as they are entering the F/D and using that crew member as a human shield. There would likely be no prior warning and the shock tactic as well as forcing any pilot who was quick enough to access their weapon and have it cocked with one in the breech during those one or two seconds would have to be a very 'ard man indeed if he were to let off a few rounds into his colleague before the terrorist and any accomplices had overpowered the crew and taken control.
I'm still not convinced that arming pilots is the way to go. The odds of having an attack on your aircraft are infinitesimal. As we have seen recently, the more likely scenario of a deranged individual attempting to storm the F/D is soon sorted with the help of pax and well trained cabin crew. Until the relevant authorities get their acts together and put into place serious measures to prevent deranged grannies, armed with nail clippers and shaved chopsticks frem getting on board in the first place we will have this groundswell of gung-ho, wannabe policemen pilots going for the arming option.
Obviously there is little faith in the current measures at most airports where the check-in agent asks the usual questions and a bunch of middle aged suits with a weeks training on how to frisk granny if the metal detector goes off. Can you blame the pro-gun proponents wanting to arm pilots with the current joke that passes for airport security?