Some really interesting rifles, there, lancaster, the Nowotny in particular.
It appears to take a ctg. The ctg. is shoved into the chamber with the holding pin to the outside at 2 o'clock.
A percussion cap is placed on the central nipple.
The hammer is simply a way of cocking the action, and the striker is internal, hitting the cap to discharge the gun.

Most interesting - at least, that is the way I see this one working- a guess, in other words.