Thank you for your e-mail. The model that you are referring is the 500 model but it's only in a phospate finish , Many marines use this models, that come with bayonte lug and heatshileds, We have models that look similar to the 590 . This models differ in that the 500 is for 6-shot and also is available in 8-shot. There are more variety of barrels it's chambered for 2 3/4" shells 5 in the magazine tube and 1 in the chamber . The 590 also have blue finish barrels, mariner , and phosphate finishes but this are chambered for 6 shot and 9 shot. For this model the barrels won't interchange with the 500 and we only have 20" barrels in blue finish . If you would like I can send you a catalog 2007 so you can see the new models of the 500 in phosphate finish and the 590 models. Thank you.