When to adjust rear sights?

Someone here once cautioned not to adjust the rear sight until after gaining more experience and developing more consistent groups.  I see now where this makes sense but how do you know when this all comes together?  Is it enough to adjust the sight after shooting 100 rounds and with the exception of a few flyers all the shots seem to concentrate in a group of about 4" at 25 yds?  Or should I wait for a tighter group?

4" group? ...I'd move the sight unless they are not on call.

What is meant by "not on call"?

What is meant by "on call"? Simple, where did you see the shoot hitting the target when you released the trigger? Did the shot go there?

It's simple.  CENTER THE GROUP!

Gus

Beeser:

I would adjust the sights

George