"I am fairly certain most com-bloc guns are/were made from recycled tractor frames.
Not necessarily a bad thing, just rest assured they aren't made from the best or the finest steels."
Fairly certain on the basis of precisely what? Got any data, or are you just relying on cold-war era prejudice? I have had TWO Colt 1911 A1 safeties snap in two due to improper heat treatment. Saw the same thing happen at the range to a Smith Model 19...three chambers blown apart, together with the improperly heat-treated topstrap. Luckily no one was hurt by the 38 Special-turned-fragmentation-grenade.
Let's see...aren't shooters concerned about low serial number Springfield 1903's with their notoriously brittle receivers? What were our countrymen using, recycled Model T's? Let's stick to facts, here, gentlemen. I've never heard of a Tok or an AK or a Mosin Nagant going kaboom. And certainly none of mine have. I can't say the same of some American made guns that I have seen and/or owned.