Mike, aint no use asking essentially the same question over and over again, see my answers to your former questions in these threads:
http://forums.nitroexpress.com/showflat.php?Cat=0&Number=241081&an=0&page=0#Post241081
http://forums.nitroexpress.com/showflat.php?Cat=0&Number=122479&an=0&page=2#Post122479
http://forums.nitroexpress.com/showflat....true#Post237830
As I wrote before, the post-1957 M-Sch "Magnum" action will take cartridges up to cartridge over all length 86 mm = 3.35", not a hair more. So the .404, max. coal 89.66 mm, the .375 H&H Magnum and .416 Remington, both coal 91.44 mm are out as is the .458 Lott. The M-Sch "long" actions from the M1924 on take a max coal of 84mm, so 9.3x62, .30-06 and 7x64 are "in", while the 9.3x64 Brenneke, coal 85.6 mm, is "out" of all pre-"1957 Magnum" actions. The only prewar M-Sch "large bore" chambering was the 10.75x68, coal 81mm. Though the original factory loads featured a 347 gr bullet at 2260 fps from a 28" test barrel, modern powders allow handloads using the 400 gr .423 bullet to achieve about 2050 fps from a 24" barrel. This is about the same as the old Kynoch load that advertized the same 400 gr bullet at 2100 fps from a 28" test barrel. The fly in the ointment: Mannlicher-Schoenauer rifles in 10.75x68 are rarer than hen's teeth. I noticed only four such rifles worldwide.