So, make it Ordnance, why? It's equally powerful to the BR and will lose out against a decent AR user in close range, the DMR is a perfectly fine weapon and allows you to pick long range as an initial loadout. The shot cooldown seems fine, and if someone has landed 4 headshots in a row on you while you're moving and you haven't killed them or made for cover, the likelihood is they would have killed you with any other weapon at that point anyway.
Also, could I take this moment to point out that the DMR and BR are identical in damage per second, if you're hitting all 3 shots, you're doing the exact same amount of damage.
And as an aside, with the BR if you miss the first shot but quickly adjust the second and third shots of the burst will land on target, creating a more forgiving weapon. If you miss a shot with the DMR, you've missed.
I will agree and acknowledge that I have beaten other weapon users at long range with the DMR, and at close range, I've also beaten enough DMR users close range with the Assault Rifle to say that you can win a CQB with an AR against a DMR if you are controlling your fire.
Though you raise a fair argument, I've also beat plenty of Shotgun, Scattergun, Binary Rifle, Sniper Rifle and Inferno Cannon users with both the AR and DMR at mid and close range, does that mean the AR and DMR are better than those weapons?