RE: scope base that allows use of iron sights.
If you ask most experienced hunters, some may have tried the see through mounts, back in the 60s and 70s...Now they have learned that if you mount the scope properly and learn how to shoot with both eyes open while looking through the scope that the are not necessary...They are an inferior mounting system they will not hold up to the recoil of a big game rifle...They also destroy proper cheek weld on the stock because they raise the scope higher than the gun was designed for...
If you need to learn how to use a scope, buy a .22 and drop a cheaper Bushnell on it and learn to squirrel hunt...