Hey i saw on the trailer that there was a new sniper, the M43A2. Why cant i see it in the game?

It's the M40A3. And it is only possible to use it in surtain gametypes. Some servers are using this mod. Just look for M40A3 in the serverlist. You can play it yourself too. But can't remember the name of the gametype :/

you can play it but only on oilrig at the moment I believe? unless someone correct me if I wrong.

 

g_gametype "m40a3"; map oilrig