I think I remember that from way back when. Didn't he call it a "calibration converter"? That made me laugh and shake my head.If anyone is interested in "Caliber Conversions" as in sub caliber barrels for cheaper target shooting (Think Sub Caliber barrel inserts or Ceiner Conversion kits to allow .45 Autos to fire .22 ammunition) then this "Columbo" Episode/TV Movie is worth a look, if it comes on in your area.
Me-TV is showing them, and that is where I saw this one recently.
"Columbo" Double Exposure (TV Episode 1973) - IMDb