I shoot "bear" ammo, the brown bear and silver bear stuff. It does good, so does Wolf ammo.
From looking at backstops I have shot, the hollow point expansion is kind of a joke, even though 7.62x39 is only a medium cartridge, the HPs still penetrate like a FMJ. Ballistically I would expect similiar effect from either.
I did have this bear ammo for a little bit that was a HP with a ball at the tip. The concept was that the ball would get pushed down the hollow cavity and cause more even bullet expansion. Realistically from inspecting what I shot it into, this ammo fragments very well instead of mushrooming out like it's intention. I would assume that makes it excellent for soft targets, and limits overpenatration to deposit significant energy laterally in the wound cavity. I cannot seem to find the stuff anymore though.
So if you want a defense round for your SKS I suggest you use whatever you shoot at the range that functions reliably and hits your target consistently. I would not put a special "super lethal" hunting round with faster burning powder in your SKS. Ballistically for your SKS the most mundane cartridge will still have enough energy and stopping power at a defesive engagment distance. Consider every round you fire HP or otherwise to still perforate through your target like a FMJ. If you need to penetrate a barrier and it doesn't, just shoot more, eventually one will.
So save your money for nice defensive pistol ammo, where it will make a bigger difference over normal fmj.
Edit: If for some defensive reason you keep it loaded, make sure that the firing pin is clean and falls into it's recess easily. If it gets gummed up and stuck it is a slam fire waiting to happen. This acident has cost lives. When the gun is empty shake it to hear the pin rattle.