Which grinder are you using? The plastic tampers are bobbins so I'd say calibrate the shot using the new tamper and forget what you were getting with the plastic one. The resulting shots should taste better anyway.
Were you getting any coffee solids in your shots previously?
Which grinder are you using? The plastic tampers are bobbins so I'd say calibrate the shot using the new tamper and forget what you were getting with the plastic one. The resulting shots should taste better anyway.
Were you getting any coffee solids in your shots previously?