I agree with Dave. I use almost exactly the same procedure. After break-in, I clean every 20-30 rounds for as long as I own the gun.
Improving rifling in an old gun is basically fruitless. The best thing you can do is follow Dave's cleaning procedure initially and again every 20-30 rounds. Bores rarely wear out. It's usually throat erosion that causes accuracy problems. Only a new barrel will fix that problem.
Some shooters swear by firelapping. It does smooth the bore but personally, I don't think it is needed. In fact if its overdone or done in an older gun, it can ruin the bore or throat. I've never owned a rifle where the bore was rough enough to warrant firelapping.