Impossible to answer without a detailed description of all markings, caliber and features.
The Value of a gun is determined by it's age, make, condition of the gun and how desirable it is.
The value of a Symonds "Keeper Gun" 12 gauge hammer-gun is actually dependent on a number of things. Some of these things would be the age and condition of the gun.
who made the gun. how do you know it's a black powder gun ????
It depends on what condition the gun is in,markings on the gun,and what the history of the gun is.
You'll have to be a little more specific. Which Gun are you referring to?
Blue Book of Gun Values
Blue Book of Gun Values
The value of a gun is determined by the condition of the gun and its demand. As of 2014 the value of the Savage 12 gauge gun is 165.00.
It is 4 and the value is 3000.00
Despite the name, it is not a machine gun. Value seldom exceeds 100 USD
re-blue deminishes gun value..................
value depends on overall condition