The 357 Maximum and the 357 SuperMag are two DIFFERENT and distinct cartridges. The Dan Wesson is chambered for the 357 SuperMag, not withstanding the fact that it is marked 357 Maximum. I don't know why this is so, the only explaination I can think of being that the 357 Maximum was available across the counter while the 357 SuperMag is a wildcat. But it has created a lot of confusion. The 357 Maximum is a shortened version of the 357 SuperMag so either cartridge will work in the Dan Wesson. On the other hand, a 357 SuperMag will not chamber in a Ruger 357 Maximum.
357 maximum is Ok for across the counterr ammo. A better bet is to roll your own 357 SuperMags. If you have true 357 SuperMag laoding data, it will perform better than the 357 Maximum. 357 Maximum brass will generally work for the SuperMag as there is only a small difference in case length, most of the difference is in bullet seating depth. I have been buying Winchester 357 Maximum brass. It comes out of the box over length for 357 maximum but just right for 357 SuperMag.