If you're talking about the revolvers; the shroud pulls off easily, once the nut at the end of the barrel is taken off with the DW tool.  On rare occasions; older models that have been left together for an extended time, or the older style of porting that vented into the shroud; required a soaking in Kroil, brake free or some type of penetrating oil to release the shroud and even the barrel in some cases.  Once cleaned, they could be removed easily.