[hoosierskypilot]

My memory's vague about this, but wasn't the .222 Remington the forerunner of the .223? Wasn't the M-16 initially chambered for the .222? Other than that, I don't recall any semi auto chambered for the .222. If it's a .222 (which I doubt) then that narrows the field, considerably. Bolt action or Thompson Contender, maybe.

Probably a .223 semi auto. Probably Muslims. Possibly going to see this kind of thing happen quite a bit.

[B4Ranch]

The 22.250 is a better round for long range shooting in my limited experience.

[js1138]

I thought that back in the 60s, Remington and Winchester had a thing going with .222 and .223. Both, as I recall, were mods of the .220 Swift, which was the preferred varmit round. The .220 was reputed to wear out your barrel pretty quickly.