the s400 will, and does outshoot any of us, and ragged 1 holers @ 30yds are achievable if we get it right

clean the barrel, then re-lead it by doing a shot string over the chrono, and then only use your best 50 shots in the sweet spot.
make sure your scope is true to a plumb line, draw a horizontal line on a piece of paper @ 30yds, get yerself bench rested, and fire 5 shot groups at the line.
dont worry about pellets striking left or right at the moment, get your shots zeroed horizontally, then take it from there

let us know how you get on, any problems shout up on here.