I've said this before, but if was me, I'd sight the left barrel in at 40 yds, and then load and choke the right barrel wide. My two main turkey guns require me to adjust my aim (I don't like dots and scopes yet), and it's never been an issue. You won't ever need the wide barrel unless you mess up and let him get too close anyway.

On the other hand, a M2 is mighty sweet...