I have a donor and a new .451/2 dia barrel that will soon be finished as a 24"+ barrel with a 8" straight major thread dia for a Savage 110 . It will taper and leave the last 6" straight at .750 . It will be screwed to an Axis donor action that most likely will be faced off to use the standard recoil lug .
As far as a cartridge goes it's a blank slate . The only qualification is that it has to be a .451 dia and fit a standard 06'/7RM length.
I may hunt with it but I'm in Arkansas so it's 100yd max unless I can get a lease on fields or a pole line . It's all thick woods here .
Things I've done in an effort to get where I needed to go for some reason. All would be rimless.
45 Colts carbine M92 at 20kpsi with a 350 gr bullet at 1300 fps MV.
A 454 shouldn't have any trouble getting a little more .
The 460 rimless 45 Raptor would use the 460 data I've gotten 1800 fps MV with a 350 gr
This gets me into 45-60 type shooting a case full of slow rifle powder and I can size bullets from a .454 RB to 535 gr to what ever I need .
I've considered the Alexander Arms whatever it's called rebated rim 45-70 but that's 458 .
Not a big deal if I'm loading it but the next generation might not .
There's the 450 BM .
No hassles with making brass or making up data but the super heavies are still grey areas .
Of course I could go full wildcat and use a full length 06' case or a WSM , maybe a 450-2.25" like the 458 American but 2.25 instead of 2" so it won't chamber a WM and it'll a long jump should a 450 Marlin or or 458 American get in it .
So there it is spend my money on dies and a reamer .