Congradulations, that will be one sweet pistol, I've never owned the 686 but it has always been one I really like and will have to have one some day. I've always liked the unfluted cylinders and have a 629-2 unfluted that I really enjoy.
I've taken only one deer with the 357 and that was 21 yrs ago, broadside about 70 yrds 8" dan wesson with a Federal 180gr factory loading of the time and it did well. 30 yrds will be no problem. Search some of Jerry Lesters posts, he seems to be the resident guru on hunting with the 357 and has some great recommendations and real world experience to back it up.