Why is the 222 loaded to only 46,000cup and the 223 is at the standard 52,000cup??. Same actions ,same case. Can I use the 5 thousandths case head expansion rule on the 222??

I'm taking for granted you mean case head expansion. If you have .005 expansion your flirting with danger. For it to be a safe load you should have no expansion.
David

One article I read in handloader mag. stated that .005 case head expansion is the sign to stop, and back off a grain of powder. Just wanted to know if that applies to standard cases(30'06) or any case, such as 222.

birddog65,
There is a lot of bad information out there. Think about a .005 expansion. The primer pocket won't hold a primer now. If you plan on reloading the case more that once.
When brass get fluid enough to move .005 from (temperature and pressure) the least little thing could cause the case to rupture and blow back brass bits in your face. It's not worth the risk.
David

You must have read .0005" or 5 tenth's as a toolmaker says. The .222 Rem case is not all that thick. I just looked up the head expansions I got with good loads going back as far as 40 years ago and they were .0002" max. I bagged thousands of critters with those loads.

Don't load too hot. It's your eyes that are just a few inches from the "controlled" explosion.