There are four .32 revolver cartridges: .32 Short, .32 S&W Long, .32 H&R Magnum, and the newest, .327 Federal Magnum. That order is also from least to most powerful. I believe (Someone will likely come along to correct me if I'm wrong) that the Taurus 731 is chambered for .32 H&R Magnum.
.32 doesn't leave a very big hole for a self defense gun, and ammo can be tough to find and more expensive. For a carry revolver, IMHO, the best choice would be a Ruger revolver, wither the LCR or SP101, in .38 or .357 Magnum. While a Ruger will cost you more than a Taurus, it won't be by a whole lot, and the better quality will be 100% worth it if this is a gun you plan to trust your life to.
Originally Posted by canebrake
"If innocent life doesn't immediately depend on it, don't shoot. And if it does, don't miss!"
Ruger Mk III Competition
S&W M&P 9 Pro Series
East German Makarov PM