If you're into meteorites, all you're going to find with a metal detector are iron-containing ones. The really good ones, like pallasites (<1% of the falls), can't be detected although some of the nickel-based ones will stick to a strong magnet.
I lucked out about two years or so ago. Why I picked up the rock, other than its color, I'll never know as the detector didn't make a peep. I soon discovered it would stick to a magnet (that is how my big digger shovel is attached to my pouch). It weighs in at just 7 ounces, but is worth about $1,500.
Your really don't need good luck, as meteorites fall all over. What you need is a sharp eye, and a bit of knowledge of what to look for.