Let me first say that I never served in the military, so I have no real-life understanding of what it means to rely upon your weapon, and the rounds you carry for it, to engage an enemy or to defend your life and lives of your comrades. I have tremendous respect for the men and women who have done so, and continue to do so, in the defense of this country and the freedoms we enjoy.
From the standpoint of ballistics and terminal performance, it has become obvious to me, over the years, that a projectile should be of a certain length, for its caliber, to provide good penetration. In direct terms, it should have a high sectional density (SD). A bullet of good construction, with a sectional density of around .220, driven at an adequate velocity, can be expected to penetrate well on thin-skinned, medium game animals. As hunting big game is the only experience I have, and I understand human beings are equally susceptible, this is what I will base my observations upon.
A .308 diameter bullet, weighing 150 grains, has a sectional density of .226, which can be expected to provide good penetration. However, the SD of the 52 grain .224 caliber bullet is only .148, while the .277 diameter 115gr Sierra HPBT has an SD of .214. Of these two, hunters would use the smaller bullet on varmints, with the expected result to be high bullet fragmentation and limited penetration. The heavier, .277 bullet, would be far better, at the correct velocity range, for penetrating larger game animals. This has been evidenced by the use of 6.8SPC rounds for hunting wild hogs, to great effect.
In order to retain the ability to penetrate, assuming an adequate SD, a bullet must have a significant muzzle velocity (MV) and ballistic coefficient (BC), such that the round has sufficient energy upon impact. For many years, in the various game fields of the world, a MV between 2500fps and 3000fps, with a BC of .300, or higher, have been proven to consistently and effectively harvest thin-skinned, medium game animals. There are many examples of cartridge/bullet combinations, in numerous calibers from .243 up to .458, which will provide this kind of performance from a shoulder-fired weapon of light to moderate recoil.
Both anecdotal and in-the-field results support the ability of the 6.8SPC cartridge to perform well on big game animals such as the whitetail deer and wild hog. With the 115 grain load most commonly used in this cartridge, it provides the MV, BC and SD expected of a big game hunting round. As such, I expect that it will be sufficient for the purposes of war, where the target is a human being. It recoils less than the 7.62x51 NATO round, while delivering more energy and penetration than the 5.56, allowing more rifleman to shoot the 6.8SPC accurately, and with good effect, than either.
While very few people can shoot a gun with a complete disregard for recoil, as Tang does, I think even he would agree that the 6.8SPC is a better choice than the .308, for sustained fire, or the 5.56, for effective fire. From what I can see, even though the OP has put together a good dissertation on the merits of the cartridge he proposes, it offers very little over the 6.8 round, if anything. I say this because nowhere in his comments does he acknowledge the importance of bullet WEIGHT, in this equation. A 90 grain bullet going slightly faster than a 115 grain bullet may be equally effective, but certainly not more so, making the proposed 6.2 OCC cartridge a lateral shift in performance, rather than a step up.
Also, I have never considered nomenclature of any significance, where a cartridge is concerned, and found that portion of the OP's paper frivolous, immaterial and frankly, juvenile. I can't see the point in quibbling over the naming of any device intended expressly for the killing of men and it is certainly nothing to be discussed when arguing the relative merits of such.