The SKS, nor the AK-47, is not designed to be a sniper rifle but that won't keep inventive people from trying to use it as one. It was not unusual in Viet Nam for us to occasionally pick-up or find an SKS with a scope mounted on it in some fashion. I even saw one, at Sniper School, where an enemy soldier had mounted half of a binocular on his SKS to make a very crude sniper system on his SKS. It sure wasn't the best but it was all that he had with which to work at that time. Using an SKS for sniping is not a common event. It seems to fall into the realm of the rare event where one-in-a-thousand people might try it. What is interesting is that both the SKS and the AK-47 fall right into the type of rifle that, in times of a major war, the Russians would try to adopt into use as a sniper rifle. Take a look at the Mosin-Nagant rifle and how it came to be a sniper rifle. The MN started off as a standard duty rifle prior to and during WW1. In WW2 the better quality MN rifles were scoped and put into use as sniper rifles. The Russians and Germans both came to the conclusion that the average sniper shot, not the maximum shot, was done at a distance of about 142 meters. Round it off and we'd say that it was done at about 150 yards or so, give or take. The bullet fired by both the SKS and the AK-47 exceeds the 142 meter distance for the average sniper shot. I tend to think that this is why scope mounts and 4, 5 and 6X scopes were adapted by the Russians to fit and work with the SKS and AK-47 type rifles. They were looking ahead, just in case of another major war, so that they could again use standard duty rifles as sniper rifles, like the old MN rifles, to meet their sniper shooting criteria. The Russians were thinking ahead for the next war about using their SKS and AK-47 rifles as emergency sniper rifles to augment their SVD Draganov rifles. I think that their idea of the designated marksman's rifle would actually be a scoped AK or scoped SKS rifle with the Draganov being their sniper rifle. This may explain why some SKS and even AK-47 type rifles are being found with scopes mounted on them.