You really, REALLY dont know what you are talking about. Its in the same ballpark of a .30-30 Winchester for knock down power at that range. 300+ yards is well within range for a kill shot.
Oh and FYI they also used a M59/66 SKS sniper variant in Bosnia.
Good job, first hit on Google.
Too bad they were used in LIMITED CAPACITY. In addition, the M59/66 is Yugoslavian, which means it does not have a chromed barrel. This actually is because Yugoslavia has no ability to obtain chromium. Therefore, they made the rifle have a thicker barrel. In addition, the barrel is shorter in order to accommodate a grenade launcher attachment. The lack of a chromed barrel and the change of a heavy barrel make it more accurate than the standard SKS models, however one must take into account that the barrel is shorter, which causes reduced accuracy.
Also, please take into account that spent shell casing hit the scope when ejecting throwing off the zero of the optics, which could be fixed, but the SKS generally puts shells straight up in the air due to the extractor location. Problem is, depending on how you shoot, shells can go in either direction.
Let's also see that the stock had to be cut away so that the scope rail was actually able to be mounted on the receiver.
All these items should tell you this was thrown together by the respective users of the rifle, and these configurations never saw widespread use.
Regarding the stopping power of the 7.62x39, that is irrelevant, we are concerned with accuracy. However, we will compare 30-30 and x39 for giggles. We do have to take into account the weight of the round, so let's say we are using a 123 or 124gr x39 round, and a 130gr 30-30 round. We see that even though the 30-30 is heavier, it actually has a higher muzzle velocity than the x39. As we increase weight on that round, which we cannot do with the x39, we see the gap widens, and 30-30 is significantly more powerful than x39, roughly 20%.
To actually take into account accuracy we would have to compare a specific weapon chambered in 30-30. Now, do you see any semi automatic 30-30's? Not often. The semi automatic open bolt design of the SKS is not made for long range distances. In fact, the rear ironsight is so close to the front one, that accuracy is a problem.
That this game includes the SKS as a sniper weapon offends me. If the scope is mounted to the receiver cover, I will be very very mad.
