Please allow dfariswheel to show up and enlighten you on Colt's history and frame sizes, as the Officers is smaller than the New Service as I recall. I'm not sure about time frame but that will factor in as well. Check link out below...
Youth rebels, age conserves; between them, they advance. The Marines will cease to win battles the moment either camp achieves ascendancy. – Robert Leckie, Helmet for my Pillow