Lloyd got it right on. Most distributors will contract a manufacturer to make a run of un uncataloged model that they in turn will have exclusive distribution of. The last few years, the stainless 5 1/2" bbled Ruger Bisleys have become known simply as Acusport Bisleys. They've had a run in .44, two runs in .41, two runs in .45 Colt and two runs of the .45Colt/.45 ACP model. The next one in .357 is expected quite soon.