The answer (after your edit) is:
bronze
I am not very specific.
Quoting Wikipedia:
Bronze is an alloy consisting primarily of copper, commonly with about
12% tin and often with the addition of other metals (such as
aluminium, manganese, nickel or zinc) and sometimes non-metals or
metalloids such as arsenic, phosphorus or silicon.
I can be philosopher
The Thinker (French: Le Penseur) is a bronze sculpture by Auguste Rodin.
or gun.
Gunmetal, also known as red brass in the United States, is a type of bronze – an alloy of copper, tin and zinc.
The sun can make me.
People are said to be "bronzed by the sun" when they develop a tan.
So can man.
Fake tan. Alternatively man can forge bronze.
A trick he learned ages ago.
Bronze was one of the earliest alloys man learnt to make. (OP: Yep. In the 'Bronze Age')
I was in many hands then.
Bronze-smithing was a trade known by many
And I fed and slaughtered the masses.
Bronze weapons were heavily used. (OP: also - Tools for farming and the like were made from bronze)
I am in fewer hands now.
Not many people can make bronze by themselves and bronze is not as commonly used as it used to be. e.g. bronze coins are less common.
And I see less bloodshed.
Weapons almost certainly don't use bronze these days.
But my clash and chime are yet revered.
Bells made of bronze still ring out today. The hammers that strike them are bronze, hence clash. Bronze is also used to make guitar strings, saxophones and banjos, which make be said to 'chime' metaphorically. (OP: also - Cymbals are often bronze and make a clashing sound)
After Silver
Bronze is less precious than silver (OP: also - Silver: Second-Place, Bronze: Third-Place)
and stone.
The bronze age came after the stone age.