Flint is right on. Flattop .44 was made from 1957 to 1963 when the Super Blackhawk arrived. Easy identifiers- Flattops, standard blue finish, fluted cyclinders, aluminum grip frames, have no side protection for rear sight, sight marked Micro and grip very much like Colt SAA (XR3). These were offered in 6.5", 7.5" and 10.5" barrels. 7.5" hardest to find. Super has raised ribs to protect rear sight, sight unmarked (Ruger built), unfluted cylinders, much longer grip frame of steel and very high polish finish. Early Supers came in a fitted wooden boxes. 7.5" barrels only until much later, then some 10.5". Both are "3 screw" or Colt SAA type actions. The "New Models" with transfer bars (and only two pins) were introduced in 1973 and both Blackhawks and Supers converted at that time. Ruger also dropped the ".357 size" frame at that time and built .357's on the .44 frame until the "New" Vaquero and commemerative Flattop this year.