I am thinking of doing a similiar project, but making a WInchester model 100 carbine in 338 federal! I cannot see why this would not work in a Savage 99C, but you may run into problems with those rotary magazines? This is a great cartridge! Very under appreciated. I got onto this after a friend showed me his grouping on his gun and told me the ballistics! As I live in Thunder Bay ,the large cutovers are far and few between since the Paper industry disapeared, so long 300 to 500 yard shots are not anylonger the norm wich makes this 338 Federal a great intermidiate cartridge for moose and deer! Good luck I will let you know how my Winchester turns out!Dale Z in T-Bay