Birch and Cap
I like Smokin Joe's design but I would want two additional features.
It would have to be right for most six shot revolvers including at least Remington, Colt, Walker, and Ruger. The biggest bolt that will fit through the cylinder for a Ruger or Remington is 1/4. And even that may be too large. I never checked. I would want the thing designed such that the wrenches were an integral part of the fasteners. Easy to do.
I saw Joe's post previously and it is ingenious in its simplicity. Truly impressive.
C clamp would work but it is important to hold the cylinder securely without marring the finish. The clamp will also permit the even distribution of force among the chambers one is loading. problem here is with loading a five shot revolver. You would have to load all five at once to avoid having the clamp go crooked.