I'm still fairly new, maybe someone can advise me on this. What frustrates me most about tank battles is that I can land 2, 3, sometimes 4 shots on an enemy and not destroy him but I get destroyed with 1 round from him. I can't get enough perk pts to drive anything but a panzer normally, and when I do roll out in a perked gv, I get killed right away from someone who's camped the spawn. Noobs like me stand no chance.
First advise is NEVER up a high perked tank in a camped spawn. If the spawn is camped I like upping the T34-85 or the M4A3(76W). Both have fast moving turrents. The M4(76W) shoots like a machine gun because it reloads so quick.
Second, understand sometimes a spawn is so camped that you just need to find another fight and come back later to see if it has cleared out a bit.
Third, the lag between you and the player you are shooting at makes a difference as to if you are going to get a one shot kill. Location of the hit is important, but I have found the lag is the deciding factor. I have on many occasions killed someone with one shot for them to re-spawn and all of a sudden I can not kill them in five shots even though I am hitting them in the exact same spot as the previous kill.
Fourth, you also need to understand that some players are such good shots you are only going to get one, maybe two shots. This is frustrating when you are new, but hang in there you will learn to range, but like flying you are going to die a lot.
Fifth, if you did not know, you need to set your views in a tank just like you would in a plane. You also need to have your controls set up where you can jump from one position to another with ease.
Sixth, to get some tank perks, just run some resupply M3's to bases that need it. It takes some time, but you will slowly gain some perks.
Just some of my suggestions, hope they help.
Fred