Tons of rifles have sintered bands (and other parts too) but very frequently they get chalked into the speed milled category. There are some interesting band variations, many stemming from Mauser Oberndorf developments. There are the stamped and welded H bands, the stamped and welded solid bands which actually appear to be two piece construction, you see the obvious weld seem on the bottom but the top is welded and finish ground, when you look closely in the light you can see file marks and weld porosity. Off the top of my head one of the sintered part makers is Sintermetalwerke, not sure if they did K98k parts or not, someone please correct me if I remembered that wrong.