Far more entertaining than a bowl of cornflakes, Kellogg's Pistol is lethal for a number of reasons. One, it's wielded by Conrad Kellogg, a ruthless mercenary and operative of the Institute, two, it's a .44 Magnum, and three, it has a ludicrously powerful special ability. The pistol does a healthy
48 damage, but if you crit, the "Relentless" effect comes into play. This refills your AP points, letting you take shot after shot in VATS. To get it, you'll need to off Kellogg in the quest Reunions.