Its been done countless times with the 30-06 so the guide seems sort of out in left field on this one. However If I can't do it with the 30-06 then I am going to the 375 H&H or 375 Ruger. The 416 Rem Mag would do the job as will the 45-70. With the 30-06 to 300 RUM the 200 grain Partition or TSX would be my choice. The old 30-40 Krag with 220 grain bullets worked well for me and its quite a bit shy of the 300 Mags. Real close shots with very high velocity rounds can be a problem if large bones get in the way.