Yeah - sorta 6x45,- it's close BUT it should be the 6x46 as the 6mm. on a .222 was and still is the original 6x45 and the 6mm. on the .222 mag. case is and always was the 6x47 - so the .223 should be the 6x45.5 or 6x46 - shouldn't it? The guess the mag. case is .009" longer than the .223 which is .006" longer than the .222.

Afterall, the .222 and the .223 are both .224's so there is some leeway but to differenciate the .222 base case from the .223 and .222 mag. case, would be to call the 6mm on the .223 case, the 6x46mm - at least here.