IIRC, the 547 came out in the late 70s when the revolver was still king here in the U.S. for home/defense/police use. I'm pretty sure the revolver ammo was cheaper then, at least around here. I shot rifles but didn't shoot handguns much until the early-mid 80s when the hi-cap 9s started becoming popular in the U.S.
Jim's Rules of Carry: 1. Any gun is better than no gun. 2. A gun that is reliable is better than a gun that is not. 3. A hole in the right place is better than a hole in the wrong place. 4. A bigger hole is a better hole.