I am about to pull the trigger on some hevi shot from bass pro. I have a gift card and a rebate so what the heck. All they offer there will be 12 gauge 3" 1 5/8 at 1090FPS....should I get the #4 or #5 shot. I am leaning toward #5.

Also, will this shoot out of the extra full 870 choke???

I have a very good pattern to 40 yards with my current set-up...but if I can try something for free then why not.