Quick question: Is it possible to upgrade the mk of a turret/hull without spending real money? I mean upgrading the mk costs a whole bunch of crystals and Im not sure how to get enough to do so without spending real money.

I am quite new to Tanki and i was wondering...are some weapons just straight up better than others like railgun/shaft? Or are all the weapons good for different jobs? Because right now I mostly use the railgun which I am upgrading but I am thinking of getting shaft. I did hear somewhere about different tiers of weapons...

Viking pls