Of course the SKS, will kill a moose or a deer. So will a 22rf. As long as the animal is close enough, to do it cleanly. When I was a kid, 50 years ago, it was common practise around my parents farm, to wait in the corn patch, until a deer walked to within 10 yards or so, then shoot it through the ear. Dropped like a stone. Same for the 7.62x39. If your emotions, are controlled enough, to wait for the ideal shot, within effective range, OK.
The 7.62 x39, has another problem. BULLETS. Yes, I know they make soft point bullets, that are legal to hunt with. That doesn't mean that they are ethical.
There was a post here about energy. Energy on target is only meaningful, if the sectional density of the bullet is acceptable. The SD of the 7.62x39, is sadly lacking. That short, bullet at low velocity, sheds energy way to fast, upon impact.
Another problem, with the SKS, is accuracy. Most of them just don't shoot all that well. There should be a few cries of outrage here. The average SKS, gives about an 8-10cm group at 100m. That's usually off a bench. Offhand is anyone's guess. Now, I will be the first to admit, there are exceptions.
In a bolt action rifle, where the cartridge can be loaded to its real potential, with heavier bullets and better velocity, as well as potentially better accuracy, it should do the job OK, again, as long as discretion is used.
I've seen plenty of horror stories in the bush, during hunting season. Mostly due to human error and poor cartridge/rifle choice. I watched a young fellow shoot a bear, 3 years ago, with his "Grampa's 30-30, with Garampa's 50 year old ammunition". Nothing wrong with the ammunition, it did everything it was supposed to do. The young fellow had a box and a half of "Dominion" 170gr, flat nose. He had shot off a box, at the range, from the bench and felt he knew the rifle well enough to hunt with. He felt the remaining dozen or so cartridges should do him for both bear in the spring and deer in the fall. Well, to make a long story short, he shot at the bear at just over 200m. He missed the first few and hit it in the ham on the third round. The bear ran away of course. He saw another bear, thought it was the same bear, much closer. He shot it in the paunch, again, it ran away. He of course, kept levering rounds after it, until he was out of ammunition and was lamenting the cost of another box of ammo.
I wanted to take the rifle from him and wrap it around his head. His father finally showed up to see what all the shooting was about. His comment was, "Oh well, the other bears will eat them, after they die. C'mon son, we need to get home for dinner". I found both bears, the next morning, one was still alive, with the hip wound and the gut shot one had actually been hit far enough ahead to clip the back of both lungs and died. The hip shot animal was bawling, like a baby when I got close enough to finish it.
Now that story may or may not be typical but it is a very likely outcome with an SKS.
I refused to take a fellow on a hunt with me this spring, when he said he was using an SKS. He had enough trouble shooting his other rifles, that I know are accurate, to compound his lousy shooting, with a marginally accurate SKS, was the last straw.
