Simplest question first. End play with the cylinder open is a none issue unless you have so much the cylinder falls off, refuses, to close, etc.
End play is normally only considered with the cylinder closed. As for what the proper situation with a Dan Wesson is, I have been unable to get an answer to this myself. It does seem to me that the Dan Wesson is different in this regard than other revolvers. Im still trying to get a definitive and authoritive answer.
As for the cylinder gap, it should be set with the cylinder allowed to move to the forward position. Nominal is 0.003 on the SuperMags and 0.006 on all others. If there is any detectable cylinder face run out the gap is measured at the tightest chamber.
A modest amount of erosion on the top strap is normal. This erosion will appear quickly when new and then slow down to an imperceptible rate. In the SuperMag light bullets at hyper velocities with massive charges of slow ball powder will aggravate the erosion. The SuperMags are meant to drive normal to heavy for caliber bullets. Save the light bullets for lite loads.
