RE: breaking in a rifle?
They are talking breaking in the barrel. All barrels have microscopic burrs and ragged edges from machining,boring,rifling. Breaking in the barrel polishes and burmishes the interior bore impections instead of embedding bullet jacket material and creating jacket fouling buildup that happens when just shooting it.
Everybody has different ideas on how to break a barrel in,so here's mine-For the first box of shells,clean GOOD after every round. Second box.after every 5 rounds. Then you are done.