No...this is not a balk.

6-1-3 allows the pitcher "Before starting his delivery, he shall stand with his entire non-pivot foot in front of a line extending through the front edge of the pitcher's plate and with his entire pivot foot in contact with or directly in front of the pticher's plate. He shall go to the set position without interruption and in one continuous motion. He shall come to a comelte and discernible stop ( a change of direction is not considered an acceptable stop) with the ball in both hands in front of the body and his glove at or below his chin. Natural preliminary mothions such as only one stretch may be made. During these preliminary mothions and during the set position until a delivery motion occurs, the pitcher may turn on his pivot foot or lift it in a jump turn to step with the non-pivot foot toward a base while throwing or feiting as outlined in 6-2-4 and 2-28-5, or he may lift his pivot foot in a step backwward off the pitcher's plate which must be in or partially wiht the 24-inch length of the pitcher's plate...[emphasis added]"

As long as the turn and step towards first is adjudged to be, in fact, "towards" first and he throws the ball to first base, then this is not a balk.

Leo