yes, there are several options available to you.
is it already drilled and tapped? if not, you will have to have the receiver d&t'd - but be very careful if going this route. the savage 99 is a desireable weapon and doing this to an undrilled receiver will not be a good thing for it's value/collectability.
if it is already drilled and tapped, you just need to get the right base. there are 2 different hole spacings that i am aware of. take it to a gunshop and make sure you get the one that fits. there are many options available on this route.
last, you could look into a tang sight or another form of a peep/iron/etc. my 99 currently has a scope on it, and i really think a scope on a 99 sort of defeats the purpose of the gun. a 99 sans scope is a joy to carry and maneuver. as soon as i can find a receiver sight for my gun, the scope will be gone. but, receiver sights don't seem to be easy to come by, and i'm not a big fan of tang sights - though many people really like them.
