Photos can be deceiving, so I don't know the degree of "cant". I will say that the position of the rear sight blade in it's housing/assembly will be load dependant.

Here is a target that was shot with my 4 1/4" M69, rested at 25 yds with the same point of aim (large center diamond) for each load. Only shot two rounds with each load to minimize recoil induced fatigue and reduce target clutter. As you can see, different loads have different horizontal POIs.



FWIW,

Paul