Complex sentence: The MK III is sold in both steel frame and 22/45 polymer frame variants, and is expected to replace the MK II. All Ruger rimfire pistols are chambered in.22 Long Rifle only.
Split into simpler sentences: The MK III is sold in both steel frame and 22/45 polymer frame variants. Currently the MK II and MK III are chambered in.22 Long Rifle only.