Try to stick a magnet to the barrel.If it sticks it's steel.If not, probably brass. Cheers,Smoketown
Earliest=BronzeMy '63 312 is bronze
I also removed the black paint from the radiator tank to reveal the brass on my first car (’51 Ford.)
Brass was used to prevent rust from moisture that can occur with pneumatics. Is that really an issue, has anyone found a pitted steel barrel? Or are they just cheaper to make?