I noticed between two of the nipples on the cylinder there is a little bump. I have been told that this is so you can drop the hammer between the cylinders, and carry with all 6 cylinders loaded...is this really safe, or should I just do 5 loaded and rest on the empty
This is a subject of much debate. My personal opinion is that it's SAFER to carry with the hammer on an empty chamber than on the safety notch/pin (on some revolvers there is a pin between chambers) with all 6 loaded. There is not a great deal of difference between the two, but the empty chamber does provide a little more security. Here's why:
Consider the hammer down on the safety notch/pin between two loaded and capped chambers. In this position the bolt is raised and resting against the outer surface of the cylinder between two stop notches. The only thing resisting cylinder rotation is the hammer on the pin or in the notch on the back of the cylinder. Pull the hammer back to the point where the hammer clears the notch/pin and the cylinder is free to rotate in either direction; it only needs to turn 30 degrees and the hammer is over a loaded and capped chamber; if it falls the gun will discharge.
Now consider the hammer down on an empty, uncapped chamber, between two loaded and capped chambers. In this position the bolt is raised and resting in a cylinder stop notch. Both the hammer and the bolt are prohibiting cylinder rotation. Pull the hammer back and the cylinder is still unable to move until the hammer moves far enough to lower the bolt; this hammer position is several degrees further back than in the above case. In addition, the hand will only allow rotation in one direction when the bolt clears the cylinder stop notch. Finally, the cylinder must rotate twice as far (60 degrees) to put a loaded and capped chamber under the raised hammer.
Many people argue that a good holster with flap or hammer stay makes the difference moot, but there is the issue of inadvertently catching the hammer on the holster, belt or clothing while stowing the gun - there's no holster safety mechanism to prevent that.
Finally, some argue that the small advantage in safety that one gets from carrying on empty is negated by the possibility of needing that sixth round. Perhaps; there are no statistics to evaluate that one way or the other.
Granted the advantage is small, but when you consider the possible damage that can be done by a negligent or accidental discharge, the choice to get every possible extra bit of safety one can seems obvious.