You need to think of pre-ban magazines as an investment. Don't wate your time and money on junk. Stick with GI magazines and you won't go wrong.

Colt magazines are great but don't pay any extra for them unless you're a collector. Truth be told the magazines are the same except for the floorplates.

Avoid USA brand magazines like the plague. Also avoid anything in discount catalogs that aren't listed as GI magazines. They will fit, but the function will be a disappointment.

You'll want some 20 rounders for working prone or sighting in off a bench. You'll find the 20's are a little bit more expensice, but they are a really nice addition to the range box.