Hi, I'm not a wildcatter or even (I hate to admit it) a handloader, but it seems to me that the .450 Marlin has a lot of possibilities as a parent case. With the belt to control headspace, it would be ideal for a neck down to .400-.416 (it is my understanding that headspace is a concern on the .400 Whelen). Also it seems to me the case would be ideal for a short bolt rifle for those who don't care for lever rifles. I think about the Gibbs Enfield in 45-70 and wonder if it would handle the .450, advantage would be not worrying about someone stuffing your hot 45-70 handloads in a Trapdoor Springfield or original black powder lever rifle. Besides, wouldn't a short woods rifle on the Model Seven or a Featherweight or Ruger Ultra light be cool?