well, woodsdeweller's twenty year record beats mine (about three) but i think that mykeal's point is well made; you should practice with the weapon often enough so that the relative age of the load shouldn't make any difference.
having said that:
if you can't use a 12 guage pump (full choke, riot length barrel, extended magazine, #4 copper plated buckshot) the sound of someone racking a round is unmistakeable and requires no translation or interpretation: "Hi there- the mess which is about to made on my wall will consist of (mostly) you bone, soft tissue, neurolgical connections and assorted other of your body parts. You would do well to rethink your badly concluded life choices in whatever remaining time you have left." then, i'd go with the M1911. if you've had stovepiping in the past, make sure that the return spring is balanced to the load being fired. once you have this issue thrashed out, you will have a very well proven manstopper.
just one guy's opinion, and no doubt worth what you just paid for it.