The "rate of twist on rifling" is caliber specific. To give you an answer we would need to know which cartridge the rifle is chambered for.
A browning safari grade rifle in a standard caliber,and the condition you describe is valued at 995-1,100 dollars.
With the serial number that you supplied,your Browning Safari bolt action rifle was produced by FN of Belguim for Browning in the year 1963.
Check the receiver.
You will need to call Browning.
This gun was made in 1995.
You will have to call Browning with the serial number or go to their website and look it up.
Serial number and features
The answer to the question is "1962". That is the year represented by the 2. The L is the code letter for Safari Grade and 10285 is the rifle's serial number.
This should be a Safari Grade mauser action made in 1964
That gun was made in 1964 - making it 46 years old.
Browning.com has a sn function under customer service
It was likely made sometime in the 1960s.