IDPA Classifier Questions

[Random]

After reading up on the classifier it seems some of the firing strings require anywhere from 3 to 15 rounds. For example, Stage 1 String 1-4 require 15 rounds. If I load 15 rounds can I do all four strings on the same magazine? Stage 2, strings 1 and 2 require 12 rounds; can I put 12 in the magazine and shoot both? Some require a fix number of rounds; that part is easy, but for the strings that do not can we double up? It would not be surprising if participants spent just this side of an eternity loading mags for this...it's understandable why they specifically say you want as many as you can get.

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Stage 1 String 5 says "...pointed down range at a 45 degree angle..." Does this imply the muzzle is pointed at the ground, or are we tipping our weak hand at 45 degrees gangsta style and forcing the ejected cartridge into the ground? The former seems more likely.