my recently purchased type 81 was also corkscrewed. We as humans can distinguish a straight line from a wavy one fairly easy just by eye sight. If it’s out by eye sight there’s really no reason to pull out the micrometers and straight edges. I deal with fine measurements on a daily bases being in the automotive field so I have come to pick up imperfections with ease. I knew mine would be bent before I ordered it. I have yet to see anything mass produced come out of China without flaws. Their tolerances and workmanship aren’t those of us North Americans or Europeans. I see it daily with automotive parts and their failure rate in the aftermarket world. I tend to not buy anything made in China for this exact reason, but I really wanted an “AK” looking rifle and the type 81 was the only option. It is what it is, mine was a newer version and still twisted lol. All I can do is disassemble it this winter and re machine the parts to make it straight. Still shoots straight as I can hit targets at 200 yards open sights. After all it is just a spray and pray rifle haha. But yea I can see how we get upset since we would expect a straight rifle for $1000 plus taxes, I do anyway. Still baffles me how a company doesn’t take any pride in their workmanship for their products that is destined for civilians. For me this rifle will never be a showpiece or collector, it just a hungry beast that eats up the stock piles of old surplus ammo haha. Enjoy your type 81’s, nobody will know it’s twisted till you tell them or they own it.