It has a...longer (and narrower) free-bore
You want a shorter throat for long, sleek bullets, not a longer one.
It depends. They gave the CM a longer throat, so more of the bullet could be seated outside the case. Was that a mistake? The leade angle matters just as much. A long throat and steep leade don't allow long-tapered ogives any room. A short throat and a 1 degree, 30 minute leade angle, like the new "long range" rounds have, allow more room. A longer throat with the long leade allow long bullets to be seated in the neck of the case, thus increasing powder capacity, and potentially allowing for a more consistent powder burn. Magazine length ends up being the limiting factor.
