Further to my above info, while in Germany some years ago my friend there was sizing down .44 cal 265 grain bullets to 10.75mm to use in his nice little double 10.75x47. With some trial and error and working through slow ignition conditions that manifested with some powders and loads, we did get the little gun to regulate quite well.

The Hornady 265 grain bullets would probably be okay in the smaller 10.75x68 cartridge but a little light for the big 404 case.
I use gas checked 400gr cast bullets in my 404 and have taken some red deer and goats with this load. Much easier on the pocket and the barrel.