For POI (Point of Impact) changes, yes. All my rifles have a POI change when I went from brake to can. Anywhere from .5 to 1.0 MIL (1.5MOA to 3.5MOA). Totally normal. It is the added weight of the can hanging off the end of the barrel.
As for velocity gains, I have seen between 15-35fps gains with the can.
As for accuracy changes, I saw very little changes. Only had to slightly tweak one load. It was on the upper end of an accuracy node to begin with, and I feel the added velocity is what caused the need to tweak. Dropped .2gr, and back to shooting like before.