Lots of opinions on how to break in a new airgun, some say 100 shots, some say 200 and up to 500 shots to get the lube out and for it to settle down. I'd certainly hope for better after a few hundred shots. Depending on your eyesight those open sights don't help, I can't use them at all, but a decent peep sight like the Williams is a different story.
Williams sight for 397