Model 27s and 28s had a flaw that most people don't know about, or don't care about. It was pointed out to me by my father many years ago after I had bought a new one. He was an ATF agent at the time, which was well before the auto craze came along.
He said you can't shoot but one shot with a Model 27 if you're shooting up. How many times might you need to shoot upwards is debatable, but I can think of a few scenarios, one of which is being on your back for whatever reason and having to defend yourself against someone standing over you. Or in a hunting situation, like a big cat or a bear in a tree.
The problem is, the cylinder chambers are countersunk, and when held in a vertical or extreme upward angle, the loaded cartridges fall back and jam the action.
I tried it. He was right. I've never known that to be the case with any other countersunk revolvers, but it is definitley true of 27's.
