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.
Comparison to known serial numbers.
This would be a Browning BAR semi-auto rifle
You will have to call Browning
Call Browning or check the serial number on their website if it is up.
Provide a detailed description of ALL markings.
1970
Most likely, yes.
By including the serial number in your question.
Impossible to value with only a serial number.
1975
100-1000 usd
No- but if you find the serial number on the pistol, go to the Browning website. Browning has seachable production records based on model numbers, and serial numbers within that model.