 Gradually options in chambering were pared down, and by 2007 the Redhawk was again only offered in .44 Magnum.However, in 2008 Sturm, Ruger & Co. once again began marketing the Redhawk in .45 Colt chambering.In June 2015 Ruger announced a production Redhawk version that supports both the rimmed .45 Colt round and the rimless .45 ACP round., Ruger achieves this multi-cartridge functionality by partially machining the cylinder for use of moon clips for the .45 ACP while still retaining enough ledge on the cylinder to allow proper .45 Colt headspacing., For several years gunsmiths have been customizing DA/SA revolver cylinders (manufactured using modern metallurgy) of .45 Colt, .454 Casull or .460 S&W Magnum chamberings to accept .45 ACP (and possibly other rounds) with moon clips in addition to the revolver's original round(s).