The LR's case is too small to turn into a centre fire.
This is the winner. Most of the centrefire .22 cartridges here are obsolete, if not on the "extremely rare" list. Finding a rifle chambered in one would be even more of a feat.
Even a small rifle primer would be too big for the case, esp shen you need to create the primer pocket, the primer would be almost the entire inside dimension of the base. Sort of like it is now... Can't see where you would be able to retain case integrity...


















































