It is very possible, right now at the range we join last month myself, my wife, and our 13 year old daughter are hitting the steel gong 300 meters out with our SKSs.
BTW my wifes first rifle was the SKS I gave her and she took her first shots at a steel ram on another range that was 200 meters out.
Amazing what can be done if no one tells you you can't do something combined with learning how to shoot a rifle properly.
One thing I'll say about the vid is methinks his accuracy would be even better if he wasn't messing with the barrel harmonics by resting his rifle on the folded bayonet.
Good vid BTW, nice find.