Theoretically do-able,......
totally impractical, in choice of platform
What, pray tell keeps the "Adaptor" from getting flung out on the ground, as you cycle the action as a "single Shot" ?..remove the regular extractor?
LEADING issues ?
....slinging undersized .22 lr lead bullets down a .223 bore
( with a GAS PORT ),....and expecting to just remove the "Adaptor" ,....go back to Jacketed ( no effect on zero anticipated?) ?
I can build the thing,....but really advise you not to run it.
sounds like a REAL DOG.
GTC