Shaving down the nub?

Shaving down the arm nub or the bucking mound?

Shaving down the mound would give you whatever shape mound the nub is when you turn up the hop. This is where an SCS nub is useful or an H nub. I wouldn't do it with the stock toothed nub because that would give you a weird mound shape. I personally wouldn't shave it down either way because I'm crap when it comes to that (found out how bad I was when I installed my r-hop and had to shave the mound). It takes a bit of skill to get it as smooth as you need to get it.

If you do it, get another bucking so you don't screw up your current one. Also remember the smaller the mound the more hopup you will have to apply to get the right backspin.