Does anyone think that using baseballs like batting practiceballs hurt the arm? Like u can tell the ball is not official because the seams are not the same ...we call them egg shell balls
If it is the same size and weight you will be fine. Not all baseballs will be exactly 5 ounces, though. As far as having different seams go, you may not get as much "bite" on your breaking pitches.
If the shape is like an egg I would pick a different ball.