I've heard a lot about the grissle plate on the big boars, that's why I used a 300gr Swift A-Frame fired from my 454 when I went hoggin'.
The Swift bullet hit a 300+lb boar just behind the shoulder. The bullet blasted through the heavy plate and clean out through the other side. Mr. piggy ran about 35yds and piled up. It looked like a blood bath the whole way.
I can't imagine that any big game cartridge, using a tough bullet, wouldn't be adequate for big russian boars.
If you intend on shooting a boar in the head, many guys claim that a .223 bullet placed between the eye and ear is all that anyone will ever need.
VH