http://www.lumifont.co.uk/omnitest/omniQ55.htm rewired knowledge of how loading a revolver works. If you don't spin between bullets, where does the 2nd bullet go? What if you spin, but it stops in the spot where the first bullet went?
Btw, this question can be gambled a bit by using the fact that it has exactly one correct answer and going after easiest cases. This also makes the details of where you put the second bullet after a spin irrelevant provided that you don't always put it next to the first one.
Often I'm surpised and delighted when problems are accidentally constructed so that "this has exactly one correct answer" provides a lot of infromation, sometimes more than half of the actual question provides.