Rule 6 Sec 1 Art.1
Turning the shoulders to check runners while in contact with the pitcher's plate is a balk.

I continually get challenged in the Chicago area regarding this rule. Coaches both in HS (lower level) and several coaches from travel times in the 13,14,15,16 yr. old levels feel that the pitchers can turn their shoulders up until they go to the set position.
Is this a misunderstanding of the rule else where or am I wrong?

You are right. Fed rules prohit turning the shoulders once engaged with the rubber, OBR allows it until set.

I get the same thing. Tell 'em they don't get paid to read their rule books, but you do. :D

Just curious... why is turning the shoulders a balk in FED? Could someone give me a little history behind this rule?

Hold your ground......you're correct in your understanding of the rule. Problem is too many umpires either don't call it or are inconsistent if and when they do.
This is where a local official's association can be very helpful. The baseball trainer should devote an entire session to balks. That would put everyone on the same page and make it easier for the few umpires that "see a balk....call a balk".