RE: Longest Shot You Would Take
Almost everyone here has already said it ... know your limitations.
Here's a personal story: I went on a Wyoming antelope hunting trip with my dad and his friend when I was 16. That year I was shooting an old Remington 780 in a .243 caliber. I was at the rifle range several times a week finding the perfect load. For me, that practice paid off. That antelope was quartered away from me when I shot him at 400 yards with a 4x scope. My bullet placement was exactly where I intended for it to go. He immediately dropped in his tracks.
Lately, I don't spend near as much time at the rifle range (with kids and all), and there's no way I would take that shot again today... but that just shows what knowing your limitations and practice can do.