What's the name of the movie i am thinking of?

I cant remember what the title is. It came out with in this last 2 or
three years. pretty sure it had bad reviews.

It was about an assassin who on one mission doesn't kill his target.
HE was the best assassin in the world and decides to leave his "guild
of assassins" and goes to some cowboy town. the guild ends up tracking
him down and he and this town basically hold them off.

I'm pretty sure that's the basis of the movie if i remember correctly.