I believe that factory specs call for .001"- .002" endshake, so if you absolutely have none, your gun is too tight. That can cause problems like the cylinder binding when the gun heats up from firing, etc.
To check it, push the cylinder forwards, and place a feeler gauge in between the forcing cone and cylinder, then pull the cylinder back as much as you can, and re-check the gap. It should be approximately the difference I mentioned above to be within specs.