There has been a long running debate over whether 147-grain subsonic 9 mm loads—even 147-grain 9 mm loads in general—are a good choice for personal protection.
With the recent move away from the .40 S&W to the 9 mm within the law-enforcement community, there are many agency-owned trade-ins for ridiculously low prices. Here are the issues with converting a trade-in .40 to 9 mm.