While perusing the internet forums recently, I stumbled upon a post that was discussing the largest shoulder-fired centerfire rifle ever made, the .950 JDJ:
The .950 JDJ is an example of the "if bigger is better, biggest must be best!" school of thought. The stats on this rifle/cannon are truly incredible.Where your typical .45 ACP handload uses 5.4 grains of powder underneath a 230 grain bullet, the .950 JDJ uses 240 grains of powder underneath a 2400 grain (!) turned brass solid bullet.(There are 7000 grains in a pound, therefore the bullet is nearly a half-pound!) This is all contained in a necked-down 20mm Cannon round originally used by the military in the Vulcan cannon. The rounds cost an average of $30 to $40 dollars and the three rifles that are chambered for it run from 55 pounds to 110 pounds. Just perfect for those places where you might need to keep something like a rogue dump truck from attacking you.
In all seriousness, while the rifle may be wholly impractical given it's immense size and recoil, the fact that a creative private individual could come up with such a concept and actually see it through to small production is really great to see, and it is that creativity that keeps fresh ideas in the firearms marketplace.
You just won't see this as my next deer rifle!