How old is your 300 savage serial number 570566?
With the serial number that you have provided,your Savage model 99 lever action rifle was made in the year 1951.
This cannot be determined without you providing a detailed description of your Savage model 99 rifles overall condition,to include the amount of original finish remaining and bore condition.I can say that your rifle was made in the year 1942.Serial number 416,000 was the last serial number of the year 1941.
I have a Savage 99 Serial No. 442287 and was quoted $1,200 to $1,500 as long as I don't tap and drill it for a scope and sling. If I did, then it would only be worth $800 to $850. It is in excellent condition, and is chambered in 300 Savage. I made the best trade of my life for it, and that was the only time I ever came out ahead...