Several comments:
Talley QD steel rings and bases are as strong as anything I've experienced for the purpose. Wouldn't bother with getting the holes redrilled and tapped, as in reality 8-40s aren't any stronger, because of the deeper threads. It makes more difference to attach the bases/screws with something to "enhance" the connection, whether thread-locker (which also helps bases stay put) or epoxy.
Would also buy another scope for backup--in the same kind of rings. Have seen more scopes "die" in Africa than anywhere else, mostly because the cartridges chosen for hunting over there tend to kick hard enough to break scopes-especially "buffalo" rifles. Have seen this several times since I went on my my first safari around 30 years ago--including on the rifle I used then.
The Remington extractor works fine--as long as its kept reasonably clean, which isn't exclusive to any type of extractor. If it's going to break, it already would have. (Ross Seyfried used a Remington 700 .416 Rem. Magnum as his back-up rifle when guiding in Tanzania--I suspect partly because, knowing Ross, he wanted to run contrary to standard "wisdom.")
Have not found a hooded front sight all that useful in Africa (or elsewhere). If it's needed as "backup," the hood results in less light on the front sight--and that doesn't help in dimmer light--which is common in buffalo hunting. Also, the standard Remington front sight isn't very tough. Which is why I prefer a stouter front sight, without a hood.
