Through careful attention to design, Federal Premium’s engineers were able to create self-defense loads that exhibit specific characteristics sought by the two prominent streams of thought concerning personal protection. The distinctly different loads, HST and Guard Dog, will meet the needs of even the most demanding self-defense practitioner.
Very helpful article. I've been a handgun owner for about 5 yrs. I bought a book called 'cartridges of the world' , here I learned most of what I needed to know. That and talking with friends and other shooters. good article to get you started and pique your interest for more info.