now that the anti terrans are gone

I hate it when numbers get thrown around so much I can't see how the result came to be.

It is 800 rpm
It is 167 dmg (in 10m)
The target is a vanguard? Rear armor resistance is 30%, type resistance is 43%, the tank got 4k HP
800/60 * 167 * (1-0,3) * (1-0,43) = 888,44 DPS, TTK = 4,50s, shield TTK= 6,75s
Your first number was a lot closer.

For any other MBT the type resistance is 41%, rear armor and hp are the same.
800/60 * 167 * (1-0,3) * (1-0,41) = 919,61 DPS, TTK = 4,35s

Those are approximated values, mainly because no tank will take damage from half a hit, no matter what mathematics say, and the fact that the tank will start burning and taking damage on its own.
These effects are negligible and not worth the effort to minimize.

A tank doesn't even have to hit you. Bullet drop isn't an excuse. I learnt to estimate the range and adjust my trajectory accordingly. It's easier to do that with the chevrons on a tank zoom optics than with a sniper's scope. Most AV engagements tank place relatively within close proximity, so being untouchable by tank shells as you claimed is really out of the question anyway.

0.75 lmg when?