Was working on a concept wildcat cart I named the 35 DTOM or 35 Dont Tread On Me in honor of the patriot Gadsten. You can't stuff a 35 cal bullet in a 223 case but you can in a 7x33 case. The 7x33 Sako case is about 10 thousandths wider than the 223 allowing it to fit up to the 35 cal. Necked up to the 35 the case will be about 1.3" long. Loading spire point 35 Remington bullets at the canalure should fit behind the internal 223 magazine rib. This should give 357 Maximum performance in a 223 AR15. This could be a sweet subsonic 35 as well with the 225 grain Nosler BT. In a bolt action like the CZ 527 this could shine even more.
Here is a pic of the 222, 7.62x39 and the 7x33 Sako.
What are your thoughts?

Boom why not just use the 39mm case?

Thus the 358 Gremlin
An improved 39 case or necked up 6.5 Grendel. See the link in my sig line. This idea was to get maximum rounds of 35 maximum performance from a 223 bolt face.