We have argued this many times in the past.
https://parkerguns.org/forums/showth...rel+steel+mark
My arguments are --
1. That we only see the
Kf on barrels marked on the rib Vulcan Steel and the
K on barrels marked on the rib Titanic Steel or Acme Steel.
2. The marks are in the same general area where the D, L and T of composite barrels were found.
3. The
K and
Kf are not found on composite barrels.
4. The
K and
Kf marks are not seen on barrels with the V, P, P.S., T or A, usually in a circle, barrel steel marks.