I have 2 Daystates (Merlyn and Airwolf) and they both give Shotgun pattern groups using a Mag even with JSB's. But both are very very accurate using a stepped or Daystates own single shot tray. In fact I've found this to be true of other Daystates I've owned in the past too.

I may give the Rowan single shot jobbie a go when I get a spare £45

Rick