Oh, no! Not another new caliber. Don't we have enough already? Well, maybe not. In recent times gun and ammo makers have kept gun writers dancing and readers dizzy with an unprecedented outpouring of new cartridges. Of course, any new cartridge is juicy grist for the gun writer's mill, but let's face it, we've milked that old cow until there's not much cream left. Just count the new .30-caliber rounds introduced in the past few years and you'll run out of fingers. And then there are all the 7mm's, .33s, .375s and .416s being endlessly reborn in cartridge cases that are stretched, shrunk, fattened, and liposuctioned. Still, there remain only a handful of basic calibers.