A Savage 99 is an excellent rifle, the 300 Savage is an excellent cartridge, and if all the thing needs is a barrel, there are people who can rebarrel it.
You can buy a 30 caliber barrel blank, give the rifle and barrel to a gunsmith, and he can turn it down to the right size, chamber it, and install it on the receiver.
You can look at barrel blanks and prices. Your Savage is not a target rifle, but most custom barrels are target grade. You can look up Douglas, or ER Shaw. http://www.ershawbarrels.com/
. Call them up and tell them what you want, they will tell you the cost options.
The whole process of blank, chambering, bluing, will cost $300 to $400, but what the heck, you will have a Savage 99 with a new barrel! And it will be your Grandfather's.