Possible, yes. But highly unlikely, and I'll tell you why. Your baseline is just too low to make that significant of a jump. This is for the average person, so it's definitely possible to hit 260, but generally speaking, you will kill yourself trying to hit 260.
Honestly, it's important to be realistic with yourself as well. We have kids in our school who have postponed their exam into 3rd year rotations because they're not getting the goal score they want on their NBME. You know what is happening? They have basically no time to study for Step, between attending their rotations for half the day and studying for the shelf. And the further you get from 2nd year classes, the more and more you forget. So having too high of a goal is detrimental because you might never feel ready.
That being said, I wish you luck on achieving 260. I really hope you hit it and prove us all wrong. But don't think that just because you're not getting that on NBMEs that you need to postpone. It may do more harm than good.