AA We are talking about a specifically designed door here, dont forget combined with the bulkhead as well. I think if you are talking about them blowing the door off, bearing in mind there would be nothing PAX side as it would have to be designed for opening from flight deck side only, then the explosion would prob kill all the flight deck crew anyway! I think if special forces take the door down you wont know anything about it anyway to be honest as you will be flat on your back (Sorry but cruel truth!)
I think you just have the mindset that you want a gun and you arent going to take no for an answer despite any alternatives that are offered. No matter what security and precautions are given...
Julian.