Why Is Batman Using A Rifle In Batman v Superman: Dawn of Justice Trailer

A lot of people are concerned over the fact that Batman is posing with what appears to be a high-powered rifle in the first Batman v Superman: Dawn of Justice teaser trailer.

Well, if we should go by the comic, the gun is useless and only serves as a means to get Batman from one place to the other. In the Dark Knight Returns, there is a scene where Batman uses a rifle as a grappling gun to go across a building where Two-Face and his men are plotting something devastating.

Throughout this scene, Batman never used the weapon in a way that would harm anyone. The sole purpose was for grappling, and that was all it was used for.