Are we speaking 6mm Rem?
if so, is it a short action or Long Action?
I am sure it was not factory....
I'd love a Featherweight in 6mm Rem on a long action...with a one in 7 twist.
6mm in the model 70 featherweight was a very short production run if I remember right it was a 1yr production run in both early pf run and the 1st run of classics. In Colorado like a dumbass I passed on a pf 6mm featherweight model 70.