Ok, I got a chance to poke around and managed to find some information. Should have known that Mr. Revolver himself, Grant Cunningham would have something to say on the topic.
(Interestingly, the Dan Wesson guns are very robust in terms of their endshake handing; the spring-loading bearing detent at the rear of the frame locates the cylinder at the forward-most position every time, and also serves to absorb a bit of the recoil force of the cylinder.)
So that explains the springy feeling I detected. It doesn't shed much light on how much endshake is allowable in the design, but maybe someone can chime in with more information.
For those who may be wondering what endshake is, and/or how to check out a revolver like you know what you're actually doing, Jim March's checkout thread is a good place to start learning.