I dont know? But I would try 28 gauge or even 410 ( It is totaly up to yoy and your wife). Stoger makes those gauges in over and under, I think. I am sorry I dont know about the 20 gauge. Another question what would you shoot at. If you have to get a 20 gauge for whatever you are shooting at you could try and load the gun up with recoil readucers and stuff.