not sure of the proper term for something like this - never come across it before - so I used the term 'sub-caliber' , although the actual caliber stays the same.
The picture shows the volume to be about half (or even less in the bigger calibers) of a standard cartridge.

What I find interesting is that it allows you to shoot very light loads without the danger of a 'detonation'
Loading data for the different calibers are on his website under 'Reduzierhülsen' and then 'Ladetabelle und Preise'

Particularly interesting in the .22 calibers -
in my case, I can load and shoot a .222 Rem as a .22 Hornet

also, I like the idea of the other type of cartridge he offers (again, this is .22 calibers only): the 'Diabolohülse', where you shoot a .22 air rifle pellet or round ball with just a shotgun primer (see photo)
This basically makes it a 'Tesching', as indoor rounds used to be known in Germany.
I have tried it today in my garden - about 25 meters on an air rifle target - shoots 1" low with the .222 settings on the scope.

Regards
Günter

Last edited by Gunter; 08/21/12 06:12 PM.