As we get older and aligning three things (target, front site and rear site. Especially blade sites) gets harder, a very low power scope (1x to 5x power)works very well for me. they will focus very close, and on dangerous game rifles that have lots of recoil the need for the iron sites is negated.
The well made safari scopes have a generous eye relief needed if you don't want to muzzle brake the rifle or be able to take the brake off if needed. (Some outfitters will not let you use a brake).
So if you have a heavy recoiling rifle, have a good muzzle brake installed and if the front sight needs to go, so be it.
Here is a rifle that I built years ago with this set up and it shot one of the best groups of my life
with a 400 grain bullet. (.034 @ 100 yards) with out a brake, but may someday wear one.
http://www.longrangehunting.com/forums/f28/416-buff-21003/
J E CUSTOM