S&W 22 Differences Mdl 17/18

I just read the thread and wanted to add this but the thread is locked. Several mentioned barrel length. The Mdl 18 was 4" only, the Mdl 17 was 6", 8 3/8", as well as 4". The real barrel difference is the Mdl 17 has a heavy barrel whereas the Mdl 18 barrel is tapered.