Let me rephrase: do I have the right to endanger your life? Is it only morally wrong if you actually get hurt?
The example you used was pointing a revolver at a person. That is clearly not endangering someone's life, that is threatening someone's life.
Let me ask you a question: Two identical roads. Absolutely identical; pavement conditions, curves, lane width, everything. The only difference is that one has a sign with "Speed limit: 50" on it, and the other has a sign that says "Speed limit: 70." Is a car going 60 down one road endangering people's lives more than by doing the same on the other?
Yes you would be endangering people on the 50mph road. The people traveling on the 50mph and assuming they are following the posted limit, are under the assumption that others are as well so if an accident happened with the person traveling 10mph more would statistically cause more harm than two cars traveling at 50mph.
Also if you traveled slower on the 70mph, you would endanger yourself more.
Speed matters as well, did you think it didn't The faster you go, the probability you will die or kill someone in a crash inches closer to 100%.
I am suggesting that is there is a posted Speed Limit and your exceeding it, you are in fact breaking the law of that locality.