Hi Cerva,
I had and M03 extreme in 30-06 last year, very accurate but alas very heavy, i went back to a R93 in the same calibre, cut it down to 18" and put a ASE Compact on it. The action is way shorter to start with it handles very quickly and is especially good on Boar.
Out of the two if you are venturing into magnum "Africa" calibres then the M03 would be great, the weight being to your advantage, if you want absolute solid build quality then again the M03, magazine capacity is 5 +1. However the R93 cycles faster, is way lighter (remembering you walk it more than you shoot it) and in my experience more accurate (0.5 MOA) in the 4 that i have had over he years. Its not less in terms of quality but just a different proposition (as stated its the same company). The R93 is a switch barrel as well.
My conclusion is that the M03 is better suited to Africa calibres, but you certainly will not be dissapointed if thats your choice.
Hope this helps.
Best regards