357 or 38 brass for reloading for bullseye

My question is ....Is there any advantage or disadvantage to using the longer 357 case or the 38 special case?

  I'm going to be using a 357 S&W revolver for bullseye precision pistol . 
  I load both 38 special and 357 cases with 148 HBWC. The loads I have worked up are slightly different between the two cases with the same powder and projectile and I don't see a difference in performance.

My No-dash 66 shoots magnum brass somewhat better. I load 2 tenths heavier powder charge than with special brass. I don’t have to scrub a smutz ring out of the chambers before I take it hunting the next time.

I used to load Speer HBWC in 357 brass to shoot in my Python. The load was 3.5 bullseye and shot to about the same velocity and group size. Other than the lack of the “smutz ring” there was no advantage.

If you are diligent about cleaning after each match or practice session, there is no reason to use .357 brass in my experience. You end up using more powder to accomplish the same goal.