As per 7.62 ammo, US or foreign, the answer above is in line with the instructions I got with my JDJ barrel, it says that US loaded ammo is within the pressure range considered safe for the contender, but that foreign loaded ammo is way to high pressure for a contender. Seems that the Encore can handle it no problem given the extra steel built into the action and barrel diameter at the chamber.
As for the 30 carbine...muzzle blast, yes, but I can't detect that the 7.62x39 has less...seems to be more. Accuracy...my super 14 barrel shoots real good, but then again, I trim my cases and I think that makes a big difference. Some folks say straight wall cases don't stretch, may be true, but the cases lengths of new brass aren't all that uniform. Since I started trimming the carbine brass, the accuracy is just as good as my 30-20 barrel...remember, this case headspaces on the case mouth. Crimp is a big deal, if your cases are trimmed even and you taper crimp, accuracy is good. As for killing a yote....if you can't kill a yote at 100 yards with a 30 carbine, you need to pick a better bullet and practise, practise, practise. I can't believe that a 110 or 125 grain bullet out of a 30 carbine won't kill a 40 lb critter cleanly.
good luck in your choice,
regards,
graycg