brownells.com
Go to Numrich Arms website, you can see a parts list and purchase a parts diagram for about anything- www.gunpartscorp.com
Go to a gun shop and buy one.
Go to the Henry website, and download the owner's manual for your rifle.
go to the newest edition of the "Shooter's Bible".
Your savage model 99E was made by savage arms sometime between 1960-1982.For a more accurate timeframe you can go to their sight on the web,and go to customer service to get a more accurate date as to production of your rifle.
Go to Numrich Gun Parts Corp.They should have what you need.
Go to Numrich Gun Parts Corp.
I expect about $600 but it could go higher. I am searching for one and they are hard to find.
The savage model 99 in caliber 250 savage is a great long distance shooter. Also, Check on other calibers such as 308 Winchester good out to 1000 yards and 300 win mag which can go even further. Types and weights of bullets really make a difference Also.
Gun shop.
I would go to Numrich Gun Parts Corp.
it was manufactured in 1941. Go to www.Savage99.com look for "Date of Manufacture" link.