22 Short the oldest cartridge still in production (including niche manufacturers)??

I'd say you are correct. I like the .22short and have firearms chambered for it.

IIRC the 22 short we know is actually more powerful than the round that was introduced back in the mid minteenth century.

Wasn't the .22 short invented by taking a musket cap, and putting a little powder and a bullet in it? Or is that totally wrong? I remember reading something like that.

I like the 22 Short. I can fit around 20-21 in my Henry lever-action.

If you measure a musket cap you will find the diameter is just about the same as brass case of a .22 short. Also, some even shorter versions have been made called CB and BB caps. These contained no powder at all and used only the priming mixture to propel the little bullet. I have part of a tin of German made CB caps. They have a pointed bullet that looks like an air gun pellet and the brass case is only about a quarter of an inch long. Out of a long barrel they are about as quiet (and powerful) as a typical air rifle. They are suitable for basement plinking with a proper backstop.

http://en.wikipedia.org/wiki/.22_CB Here is what Wikipedia has to say, The short on on the left looks just like the ones I have.

The information I have indicates BB was the abbreviation for breeched ball as in a round ball loaded through the breech instead of the muzzle and CB stands for conical bullet.

Paper cartridges as utilized by Sharps rifles and carbines and specialty brass cases used by early breechloaders such as the Gallagher and the Burnside are still offered through some specialty dealers but the .22 short rimfire remains the oldest self contained cartridge in continuous production.

He he,

"developed for self defense" to that I say [citation needed]