No issue with handloading. The 45 raptor was only available as a reloader only cartridge for years and my 338 edge is still that way.
The 240WB cut at 1.8" and a .429 expansion mandrel seems pretty easy. With a generous throat and a bear creek ballistics 44 cal bullet, could be rather special.
I use 240 Weatherby Mag. brass to make my 40 x 1.8"....just cut and resize....no worries about brass to short...because it uses the magnum rim to head space on not the case mouth....
Using a 30-06 just creates a problem like with the 450 BM....case gets hammered forward at the shot eventually making the brass to short....unless you use a Winchester model 70 pre-64 type action....I have found out the claw helps hold the cartridge not allowing the firing pin to push the cartridge forward upon firing...
I have a Winchester model 70 50 B&M SS controlled round rifle it uses 325 WSM brass cut to 1.65" I have shot cartridges 30+ times and still waiting for them to be to short and running them just over 60'000 psi....I have fired 450 BM in AR-15's , Ruger Americans and Christensen Arms that the most shots before a case got too short was 6 shots most around 3....