A look through firearm history will show that a "rotating" (cylinder revolving) semi auto has been done. Caseless ammo has been done. I believe that the ratchet type trigger system would fall under NFA rules.
There are threads about doing such things, and BATF has a lot of good info in their FAQ area.
Considering the restrictions we have to work under, the firearms world is doing a good job of coming up with new stuff everyday.
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)