The United States Practical Shooting Association is the American affiliate of the International Practical Shooting Confederation, like the Aussie affiliate noted below. The downloadable rules are here.
Apparently American Handgunner has a IPSC postal match (where you mail in your results) every year. Here are the results from 2003 on back. Here is a diagram of one of the match stages. You start standing in Area A, facing center of barricade with flat hands on Xs, and on start signal, draw, and from Area A shoot T1 through T4 and P1. Each target T1 through T4 is shot at least twice, then you shoot P1 (the popper) until it falls (one solid hit). Only your best two shots are counted on targets T1 to T4. The winner of this stage in the Revolver category finished in 9.11 seconds. Since that is a minimum of nine shots, and revolvers hold only six shots, that includes one reload. The shooter got 41 points out of 45 (five maximum points per shot). Youza!