They work fine on gobblers.
Sorry about the crappy cell phone pic. This was a 20# bird taken from 30 yards with a head shot. Federal #4 3 1/2" magnum load with flite control wad, extra full turkey choke. This is a very reliable gun, so long as you do not short shuck it.
When you nail a gobbler, you won't notice the recoil. I have never bothered with anything other than standard optics so I can't speak to how the ghost rings will work.