SKB,
I'm not sure if I know what a barrel striking file is, but if it is the same as a "lauf hobel"( barrel plane). A modern one is a square file ( about 1"square) 6-8" long without a tang , with different "cuts". It is used lengthwise of the barrel to level out milling marks. I could not find one in the US and asked a friend to bring me one from Germany, but he mentioned it to Helmut Kerner and Helmut sent me one his grandfather Emil made. Being old and well used, it is a treasured gift, but doesn't work well on modern steel. Consequently, I approximated one by buying the largest square file I could find( 3/4" square) and cutting both ends off. Properly used, it is one way to avoid rounding off an octagon barrel.
Mike
