Doing wrong for right?

Perhaps but isnt a better question should you?

If your own moral code is not to kill people for your own advancement my response would be, dont break it ever, regardless of what you think you will gain. If on the other hand it is something smaller like say, "Dont expose your boss for stealing etc...well thats a bit more flexible."

 

What about people who don't use a code?

I justify everything I do purely based on outcomes, and I strive to create the best possible positive outcomes. So, as @Eventhorizon illustrated, having a "code" like that for things just creates an unnecessary extra step in my point of view. It's way too much to think about, and there are usually so many factors to consider in real life complex situations. I just start from trying not to get to the worst case scenario and work backward from there.

OP smells of Fi.

 

I think of J and P in terms of rigidity/conformity scales. Those with a strong J preference tend to exhibit less of an ability to be adaptive and when coupled with a value based judgment system (Feeling) means that they are more entrenched with their own ideals and less likely to change their worldview. Creates a stable sense of self but a more black and white way of thinking. With such strongly held views, it means that experiential or out of the norm situations tend to be downplayed or ignored as reason's to alter one's perceptions. Thus creating an inability to achieve maximum benefit from experiencing things outside one's world view.

 

Anyone who tells you that they have a "code of honor" or some shit that they literally never disobey is either lying or being obstinately ignorant of the context unique to different situations. Sure, it's important to try and be consistent in your actions so as to quell cognitive dissonance, but it's not like committing one act you consider immoral instantly makes you an irredeemably awful person.

Naturally, you will come across situations in your life that require you to do things you don't like to produce the best (or at least a better) outcome. If history has taught humanity anything, it is that reality is context; it does not suffer black-and-white thinking.

 

Can you give some examples [MENTION=5559]Cornerstone[/MENTION] ?

 

IMO the crux of the situation would be if you had the capacity to understand that you might be called on to change or cross what you consider internally held belief systems. It is the degree that you believe that your moral compass/ideal is fixed that creates the strife. We tend to ignore what we are unable to acknowledge. So, I would say that we cross the line more often than we think when it comes to our moral code but refuse to acknowledge that we have done so. It is only when we become incapable of ignoring this that we face our moral crisis or outrage. However, one is always much better off being AWARE of what they are doing than to be blind to their actions.