Not able to buy the pilot gun, dont know why. Clicks on to buy it but nothing happens after clicking remains same. Do i need to upgrade tank before buying it.

Its just a glitch. The gun is bought and registered in your account the first time you buy it, but the bar never fills up.
So, just buy it once and it'll work. Don't waste your coins on it again and again.

Yes. Don't waste your coins on it again and again........... and again and again.

Yes i hv manier times ,but will see using it in game then will reply back to u.

Mate i dont know but i see gun in his hand . some say m suppose to buy ammo as well. Does the sign comes along d parachute and the gun. The question arises from as i am still not having the fire button wen m in chute.