I have a hunting buddy who has shot nothing but Remington 700s for big game for many years. He bought a Win 70 as a DG (buffalo) rifle. He had such trouble with the ergonomics--mostly the safety--that he went back to using a 700. So i concur with the advice to stay with what you know.
You might consider a .416 Rem by the way. Load it down to about 2200 fps for a 350 Barnes and it really does not kick so much, but will do a number on a buff.
The CRF crowd will have a fit, push feed 700 in Africa. Yuck...
My good bud killed a 41" buff in Zim with his .416 RSM. The PH thought the big Ruger was a good rifle, just too heavy.
His rifle, a push feed M-70 in 416 Rem.
Go figure.
DF