Wildcats are customized calibers, usually from existing cases with the dimensions changed.
I think the greatest thing about wildcats is the names.
But what about some others? The 12 Gauge Rifle From Hell http://www.thehighroad.org/showthread.php?t=178655 reaches up to 18,000 foot pounds. I suggested it should be called ".729 Redneck."
So, one of the fora I'm on started a thread.
The .2 Pac. Used for drive by shooting of rap artists.
9mm Doubletap. A perfectly standard 9mm. We just wanted to remind you of that.
.357 Excedrin Headache. Cure yours by causing theirs.
10mm JBT. If they're going to do it, they need to do it right.
10mm Vasectomy. Because we all know someone who needs one.
.45 MRI. They need this, too.
.451 Fahrenheit. A .308 case necked to .45 and shot from a 6" barrel. The muzzle blast will take care of the paperwork.
.50 Cent. When you want to make sure you get rid of the rapper with one shot.
ON TO THE RIFLES!
.23 Skidoo. A necked down .30-06. For grandpa, who can't shut up about how much better things were 80 years ago.
.300 Spartan. For sniping Persians in a completely epic fashion.
.458 Darwin. For hunting endangered species the right way.
.499 Feinstein. a .50 BMG shortened 2mm to get around California's ban.
.6000000 Holocaust. Oh, we're going to hell for that one.
.666 Antichrist. For time traveling back to hunt dinosaur.
.729 Redneck. a 3.75" 12 gauge slug, brass cased, for rifled bores. http://www.thehighroad.org/showthread.php?t=178655