The 360 was only produced at the Norwich plant, the last maker of DW revolvers that was bought out by CZ. The cartridge is between the 357mag and 357Supermag in length. It was supposed to be a super ram gun, and being shorter the frame would be lighter than the supermag that often was very near the weight limit allowable for competition. I believe only DW made the rounds or had them contracted out, the bullets are very rare, but owners of the 360 just cut down 357SM shells, which are still surprisingly available from multiple sources, although new ones fetch a premium price.