The fellows in Lever Arms will help you out. Just don't try to impress them with your knowledge. Let them know you're a newbie. They'll respect that and help you out. Worn rifleing is very easy to spot. With an SKS, unless you strip off the bolt/cover you will only be able to check from the muzzle. Ask for a bore light or bring a piece of white paper to reflect light into the chamber end to view from the muzzle. Look for small pits or frosty appearance. If you see any reject the rifle. The lands will be quite obvious. Check to make sure they are smooth and bright all the way down. You may have to brush out the bore first, to remove lint, dust or grease. It would also be nice if you can find a rifle with original, matching numbers that are stamped, both on the stock and on the metal. The stock may have ###ed out numbers and be restamped, OK but not quite what you're looking for. Try to avoid electropenciled numbers on the metal as well. None of this will have any effect on the rifles functions, so if you're just looking for a shooter, don't worry about it. Also some people like polished, rather than painted blots and or gold colored bayonets. Many things can be and are important to a collector that aren't to a shooter.
I haven't heard of any Russian SKS rifles with bad bores, other than some of the SIR offerings. As far as the bores being chromed, anything with a 1953 date or later should be OK. Personally, I wouldn't be to concerned about a chrome lined bore. You still need to clean up properly after shooting corrosive ammo.
Maybe take a look at the Marstar site. They have Yugo SKS rifles at fair prices and IMHO they are the best of the SKS family.
