Im not sure of the clearance needed for a round like this. the more clearance the easyier it will feed BUT the less accurate it will be and the more the brass will get worked. I figure it would be very wise to consult a reamer manufacturer at that point. I am thinking also that IF I have a reamer made I may have it done with out a throat and ream the throat seperatly with a $30 throating reamer that way I can adjust barrels down the road to work with differant seat depths and free bore dimensions.
By the way I did not have to aneal the rounds made from 30-06 it was once fired remington brass. The 308 brass I have is military and the base is slightly bigger .469 vs .465 of the 06 brass. 308 brass could likely be used if the neck and throat were anealed and expanded straight as the neck area will be needed. just thought it was worth mentioning.
I also made one round out of some 270 brass and it was the same as the 06.
the beauty of this round is that any casing with a .465-.470 base can be made to work if it is 1.850 or longer. making it easy to find brass and a lot cheaper to shoot than the 450 BM 458 SCOM 50 BEOWULF!!!
the only down side to this round is limited bullet selection vs the .458 and a very slight powder capacity loss. From what I can tell the other round like the 458 scom are clasifed as pistol round are not that HOT to begin with so I dont expect to see much differance in MV and energy. in fact the 44 is likely to have a better MV especially with the lighter bullets it CAN use that the others cant.