what does nerfed mean? sorry

I just checked smoky crit, there is a 10 damage difference between smoky crit and rail minimum damage, both m2s. I just read a few posts, they disagree with this. Is this new thing from update? BTW smoky is also pretty deadly on test server.

Takes some practice, but love rail. Also love freeze though. But on the test server, rail and hornet (which is a very common combo, very formidable in ranks of lieutenant and somewhat above) is horrible. I'm assuming rail gun isn't a good choice at generalissimo. In fact, I've noticed thunder and viking as a very powerful combo. Have to try it out. What I don't get is in the stats of rail gun it says damage is, say, 123-160. What does this mean?