I was going through some early parts set aside for projects. Among these parts were about 12
gas tubes which I checked with a magnet, only one was steel as the magnet attached itself.
My question: when were the steel gas tubes replaced in service ? I have a three digit Colt
SP1 semi auto sporter which does not have a steel gas tube and this is 1964 but were these
gas tubes still in use in service rifles ?P1010012_0002.jpg