For the year he went (1909) I think TR made some good choices in rifles and cartridges considering what was available. Of course, being an American he wanted to use American made rifles as much as possible. I think that was a big part of his decision to take the .405 Winchester in the Model 1895 even though the .405 was probably not the best medium bore available at the time if British and German cartridges are included in the list of potential cartridges to choose from. The .405 was probably the best American medium bore at the time (but there weren't many to choose from).

Still, if I were to journey back in time and join him in 1909, and funds were not a concern, I think I would choose the following:

Light rifle: 7x57 or 8x57 in an Oberndorf Mauser 98 sporter
Medium: 9.3x62 in an Oberndorf Mauser 98 sporter
Heavy: Either a .450 NE or a .470 NE in a British double rifle

IMHO, that would have been a fairly state-of-the-art battery back in 1909.

-Bob F.