Difference between the 6.8 and the 7.62 as far as factory loads is the versatility of the bullet and load. Most factory 7.62 is in the 125 grain area. The 6.8 can be bought from SSA in 70 -140 grain and with tactical load option. You have the ability to play with long or close range in the 6.8.
I've only shot one deer with my SKS and my son shot one with it as well. My bullet placement wasn't optimal and the deer went about 100 yards before dying. My son's deer died at impact with a solid chest shot at about 40 yards. From this very small sampling I'd have to say it's fine for close work on deer size game. By the way, we both used Winchester soft point ammo.
"An unarmed man can only flee from evil, but evil is not overcome by fleeing from it"
I have two SKS's and I have shot alot of metal targets with them. They have the power at short range. But I have found that the accuracy in both my russian and chinese model suck any further then 100 yards. In a bolt action rifle I'm sure it would do alot better. I wished savage or Remington would make a bolt action for thos round. It would be a food deer/varmit rifle as well as a good target rifle for the family. You can buy hunting rounds for these guns. It sounds like the main issue is how far should someone shoot a deer with this rifle. I think the issue should be how far to shoot a deer with a honest hunting round made for for a certain rifle. Sks to me no further then 100 yards with open sites and 250 yards with bolt action and scope if you can achieve a decent shot pattern. 300 yards if you hit the deer will kill it but I haven't found any bullets that are that accurate yet. Just my opinion and it could be wrong.
Or get a CZ527. The Walnut Furniture is just nutz.
if you like the CZ just as it comes you will be fine,,, my issue is i dont like irons on a bolt gun or the barrel to be drilled and tapped, that and cz is very limited on aftermarket stocks which is why a savage 10 or a remington 700 would be very nice to have