I would say two things: It must be accurate and dependable. So the manufacturing tolerances must be tight and the materials the best available. Cheap revolvers are abusive to the relationship. They spit bullet material out the sides, are inaccurate, and often break. The other important consideration is ergonomics. The revolver must feel “right” in a shooter’s hand and be comfortable to shoot. In the big-bores, that’s even more important. There is one well-known double action revolver that I left off consideration for this piece. It’s a tough, reliable, accurate revolver, but in the big boomers it’s painful to shoot.