In my experience I have found the following to work well pretty much across the board.
H&N FTT
H&N pretty much anything.
Crosman Premier’s
RWS Meisterkugln(SP?). This stuff is great in the pistols
Diablos work well but can be hit or miss gun to gun in my experience
RWS Hobby work well in lower power guns in my experience.
At the end of the day they are a lot like .22s in that individual guns might like an particular ammo.
All I know for certain is you will LOVE that R7. It looks beautiful, it feels great and it will shoot lights out. It’s nothing like the “Toys” you buy at the local sporting good store or Walmart. It’s a real gun, made with real materials and craftsmanship with real pride of ownership.
Folks who’s only idea of a pellet gun is the BB gun they had as a kid or the low end Gamo they picked up at Walmart have no concept of the VAST difference between those and a gun like this.
Take care and shoot safe.
Chris