The number itself wasn't necessarily "lightly struck". The number was stamped on the Fox barrels before finishing, as a reference to the barrel finisher stating the beginning "weight class" of the barrel set. Whether or not it is visible, and the degree to which it is, was determined by how much metal was struck off the barrels in finishing, to help get the weight of the gun to where a customer ordered it.

SRH

May God bless America and those who defend her.