how should play longer help me buying more expensive ammo?
the point is, if i use the more expensive ammo, playing longer wont get me more credits. you cant grind to pay for premium ammo on a regular basis.
premium tank + premium account will make enough money to pay for it, but here we are again: free to loose.
You aren't supposed to use the expensive ammo every game. I have a premium account (this is rare, usually I play without spending any money) and I still won't use it every game. Premium players have to use normal rounds for the majority of their shots too, or they will be in the red also. Premium tanks, maybe not, but that's an issue I already said should be fixed.
Most players are only going to bring 3-4 shells into the match. If you're bringing more then that and as a result can't make money, the problem is no longer you wanting to be on even grounds with everyone, it's that you want to have an advantage over everyone. Advantages aren't free. Before, gold round users had an advantage you could never get, but now all you have to do is play a tier 5 a couple of matches and suddenly you've got the same exact gear. This isn't an improvement to you?
And yes, you can grind for gold rounds on a regular basis. One game in a M4 sherman should sustain 10-15 gold rounds in a higher tiered tank, which should last you at least half a dozen matches.
Only guns that will be more effective are HE. Every gun only gets increased pen with their rounds. If you angle and you're in the right tank you can still bounce pretty much everything, so I don't see the problem.
All guns are more effective with premium ammo. My T34's pen goes from slightly above IS-3 levels to slightly above Object 704 levels with it. HE gets a much bigger boost, sure, but the pen boost for AP rounds is great. I will sure as heck benefit from being able to frontally pen tier 10s.
Also, some cannons get more damage and pen. For example, the Konisch on the VK3601 and several of the new british tanks get a good 100 point damage boost.