Welcome to the forum. I'm afraid there might not be too much informed comment on big bore airguns here as this is a British forum and the minimum legal muzzle energy for shooting deer is way above even the most powerful exotic Barnes or Quackenbush; furthermore bowhunting of any kind, including crossbow, is banned in Britain.

Needless to say that will not prevent us gaining some vicarious enjoyment from reading about other shooters' use of high powered / big bore airguns in other countries.

Adrian