I thought this was interesting:
2011 IDPA World Shoot Ammo By The Numbers
http://www.idpa.com/blog/post/2012/04/30/53-Handload-2011-IDPA-World-Shoot-Ammo-By-The-Numbers.aspx
If "money is the mother's milk of politics" then certainly ammo is the mother's milk of competition. While Jesse Unruh's famous quote isn't an exact fit for the shooting sports, there's no denying that without ammo there wouldn't be much in the way of actual shooting in the sports.
When it comes to ammunition for competition there are two routes shooters can take. One is buy factory loaded ammunition and the other is to reload. It's difficult to say without a broader-based survey how many IDPA members reload, but the survey results from the 2011 IDPA World Shoot (found on pages 26-33 in Vol. 15, Issue 4 of the Tactical Journal) give you a good idea of the possible trend among the sport's most active shooters where 53% handloaded and 47% opted for factory loads.
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