Yes, my notes show acusport having a run of KM77RFP Mark II's in .264 as a special distributor item, but I haven't had any sn's reported of that one. Then there was the 50th Anniversary KM77RP skeleton stock in .264 that Acusport and Go Sportsman received a little over 1,000 of (had Ruger 50th Anniversary rollmark and 1 of 1000 on the floorplate). I have a Ruger production list here from 2001 that also showed the .264 in the skeleton stock KM77 RP Mark II, but again I don't have any sn's documented. Ruger also made a few BBZ laminated stock stainless guns in .264.
Chet15