If you're the sort of player who loves taking out enemies from afar, the Railgun in Tanki X is the closest you'd get to actually getting a sniper rifle.
Similar to sniper rifles and yet unlike most guns in the game, the rate of fire on this turret is quite low. However, once charged up and ready, which will admittedly take some time, it can deal devastating damage from afar, allowing you to one-shot an enemy tank if you managed to hit it squarely in the spot.
Despite being touted as mainly a long-ranged weapon due to its unlimited range, the Railgun actually works well at any range provided that you have the skills to match. In fact, if you can pull off a hit in close range, you can deal a heftier punch.
The Railgun is also suitable for any hull, but if you are not skilled enough to handle its strong recoil, you might want to stick with sturdier hulls - mid to heavy hulls. Lighter hulls may provide you with far superior flexibility when moving around, but you may risk flipping yourself over when you fire off a shot.
Due to all its advantages, it's not at all surprising to see that the Railgun is a community favorite, particularly among the "pros", in Tanki X. Regardless of battle modes, there will be at least 1 player who uses the Railgun, but most of the time, you'll see several more of these guys running around, trying to one-shot every enemy they spy down the barrel of their Railguns.