They look like Russians as far as facial and body structure so i am assuming they are either pure or have very little domestic in them.
On a Russian Boar if you measure from the front of the nose to the back of the whet, back of the whet to the front corner of the eye, from the front corner of the eye to the "V" at the beginning of the ear canal, and from the "V" to the tip of the nose, all 4 measurements should be pretty close if not spot on the same measurement.
On true Russians the top of there head to the nose should be pretty flat. The more domestic they have in them the more scooped there face will be.
I have mounted a lot of Wild Boar, domestic, mixed, and true Russian.