Sorry not much of a catch. Alliant web site shows that for a 155 GR the max is 8 GR of Unique. They don’t list a 135 but with the lighter bullet you’re well below max.
Just make sure you check your scales, the other thing is to drop 10 charges into your scales and divide by 10 to make sure your average is the same as a single charge.
When you dump powder into a case it’s still somewhat loose and a “little” compression is ok, in fact as Loader9 stated, the fuller the case but better you are.
And I agree with it being very dirty. Give W231 a try.
http://www.alliantpowder.com/reloade...29&bulletid=40