Short answer yes, middle number is date, which is 1971 = corrosive.
Long answer is it seems to be a mixed bag of corrosive and non corrosive in the crate, but you can't tell without pulling every bullet to test each primer, which makes it so you don't actually get to shoot any of it. I had a crate when lever first posted it as non corrosive and probably had 400 or so rounds with no rust, no problems, but then the next few hundred rusted my sks pretty badly, so you should treat it all as corrosive and it's a bonus if you get some that isn't.
