These Circle Fly .025" over shot wads are typically glued in place over the mouth of the case to hold the shot in place. The correct size for your particular gun may vary but the following are manufacturer's suggestions. Turned cases use the same gauge wad as the shell except in over sized chambers use one or more gauge larger over shot wad. Extruded brass cases should use one or more gauges larger ie; 17 gauge wads in 20 gauge, 10 gauge wad in a 12 gauge shell etc. over size chambers may require an over size wad to easily hold the shot in place.