Impossible to value with just the serial number. Need a detailed description of all markings, features, condition, finish, etc..
It was likely made sometime in the 1960s.
You will have to call Browning.
The suffix of M71 was assigned to the Browning model BAR(Browning semi-auto rifle) which was made in the year 1971 in Belgium for Browning.
You will have to call Browning
It has not been made yet.
what is your question?
Call Browning or check the serial number on their website if it is up.
200-2000
1970
700-1000
We need the model and condition.
Sometime in the 80s. You will have to call Browning to narrow it down further.