World of Tanks question...?

The matchmaking of your tank isn't affected by the tier of it's gun or any other upgrade. Each tank has a specific matchmaking value which remains the same no matter what crew, upgrades, shell type, camo, consumables, equipment or elite status it has. You can see what tier range each tank will face in battle in the official World of Tanks Wiki (link below). The value each tank is given isn't just based on tier, although that is a major factor. But nothing you can do to a tank will affect it's matchmaking.

I have heard rumours that for the first 20 battles in a tank it gets slightly better matchmaking (I.e. Gets put near the top more often) but I don't know how true this is.

It is the tier of your tank. If you are in battle tier 5, even if you are stock you have the same chance of seeing tier 7 and tier 3. Some light tanks are classified as 'scout' tanks and they get matched as if they were a tier higher. So a tier 7 medium can see a max of tier 9 but a tier 7 scout can see tier 10.

Hope it helps

Another important element are Premium tanks, which are not included into Tank Trees and can be purchased only for in-game Gold. These vehicles cannot be modified, they have no heavy guns or impenetrable armor but they are a good way to make profit. With good tactics, they can earn large amounts of Credits and experience, the latter then can be converted to free experience with the help of Gold.

The game sucks... thats ma anwser