Agree with Ben. If gun weight is the issue, or you just want a 20, then perhaps that's the way to go. But if you like your 12, just not it's recoil, load up some 3/4 oz weenies. Most MEC 7/8 oz bushings throw just over 3/4 oz magnum shot. Something like a clear Duster wad along with Red Dot or Clays at 1100-1250 fps and you will have 20 ga performance or better without the outlay for a new gun and reloading equipment.

Sam