I've been wondering what the advantages of 10mm rounds are specifically. I haven't seen very many 10mm handguns, just a few here and there, so I gather that they're obviously not as popular as the other more common calibers. Many sources refer to the 10mm as a "Hunting Round", but I've also heard the phrase "When in doubt, get the 20 out" (referring to the Glock 20 10mm as a self-defense carry weapon), so I'm a little confused as to the intended application for this particular caliber. So... What is the intended application for this caliber (ex. Hunting, HD/SD, Carry, Zombie Invasions)? Under what circumstances would you prefer to have a 10mm over any other caliber? What makes them unique? How does the bore size compare to .357 .40 .45 .50 (smaller/larger)? What's the difference between a 9mm and a 10mm? Just 1mm larger? Or is there more to it than that? What is stopping the 10mm handguns from being as popular as other calibers (if anything)? Would a 10mm handgun be a worthwhile investment for a recreational shooter, or is it not really worth it unless you actually had a REAL purpose or need for it?