Small light green box is US surplus 308 made in 1982. This is brass or steel, it looks brass but I am not sure if it is reloadable or non-reloadable. Are these corrosive for that year?

Larger dark green box is Chinese 308 made in 1993, another box is 1992. I believe it is steel case copper washed. It says non-corrosive but I heard there is a chance that the Chinese communists sometimes put corrosive primers in them. We’re they still loading corrosive primers in 92/93?

The round on the left is American and the right (orangish colored) is Chinese.

Any info on the headstamps?

Top box is corrosive primed from what I remember. Was commonly found at Dunham's

+1

I agree.

Top (light green) box is S&B ammo.  Definitely corrosive primed.  I've shot a case of it in my M1A and done clean up with black powder solvents/cleaners with some carb/brake cleaner sprays followed by standard cleaning solvents and then lube and reassembly.  No issues if done properly.  Just shoot it up before you find yourself in a situation where you don't have time to clean up after shooting it.

I've got a case left I need to be using up to saver the SA and other stuff.

Yes, the top box is Czech, and corrosive primed.

The Chinese stuff in the boxes with the commercial head stamp is probably non-corrosive. The Chinese 7.62x51mm that came in the spam cans and/or has the typical military style head stamp is corrosive primed IIRC.

Personally I would test the Chinese boxed stuff to be sure.

Gun shop told me the top box was US non corrosive and the Chicom was non corrosive so I bought them and shot them in some of my grandpas surplus rifles. I looked the barrels over with a flash light last night. Shot them on Saturday. I didn’t see any corrosion or rust. I called gramps. He said “shit, now I actually gotta clean them” followed by “don’t buy that shit again.

I think he was trying to take a relaxation day. When he cleans, it’s OCD like where it will take hours per rifle. I would help him but he lives 5 hours away and I have to work.

Thanks for the info. I guess the people at the shop didn’t know a damn thing about either box.

Top yes. It was also sold by the case at some of the surplus places as being from one of the former com bloc countries. The Chinese ammo is a maybe.  The Chinese do not believe in truth in advertising and I rusted up a Mini-14 many years ago with Chinese non-corrosive ammo.

Corrosive ammo is a funny thing.

I've shot it in an AR and "tested" it by waiting till the next day to clean it.  No issues seen.

Then I went a couple days.  No issues seen.

Then I went a week (but looking at it every day just in case).  No issues.

Then, one day, while shooting down in NC when it was kind of misty/damp/foggy I shot it, drove the 3 hr. drive home and waiting till Sunday morning to clean it.

HOLY SHIT!!  I had to beat the bolt open.  Lugs on the bolt rusted, lugs in the barrel extension rusted.  Rusty looking fungus growing on the tail of the bolt.

Metal in the lower was fine.  Barrel was chrome plated so no issues there.

Flash suppressor had rust in it.

Took a lot of scrubbing/brushing/cleaning to take care of that.  Only pitting was on the bolt tail.  But pitting??  In 14 hrs.??

And I'm a compulsive over luber.  It was plenty wet with Mobil 1 when I started shooting it Saturday morning.

If you live in the desert there's not much moisture from the air for the salts to get sucked up and deposited on the metal surfaces.  But all it takes is a really humid/damp day to toss things out the window.

I'm not saying don't shoot it.  I'm saying clean it ASAP and then check it every day for 2 or 3 days to make sure you did get it all cleaned out.

That Czech ammo was pretty accurate and reliable in my M1A.

What corrosive ammunition were you using in your AR?

Yes.... I was going to ask the same question:  What 223 ammunition is corrosive?

Doesn't really matter, though, the advice is still sound.  
If in doubt clean your rifle ……… check it a few days later.
Yes, humidity will accelerate the process......

The Chinese .223 was corrosive in random batches. It was all marked non-corrosive on the boxes.

Yes, common knowledge for those of us who have been around a while, but was he using this ammunition?

What other .223/5.56 has been commercially available that is/was corrosive primed?

Chinese .223 in yellow boxes was common in the early 90's (9mm also) the headstamp had a triangle if I remember correctly.

It's all marked non-corrosive but with the Chicoms you never know. Sometimes it just means mildly corrosive or a little less corrosive...

I remember in the 80's, I would buy and shoot Chinese AK ammo that came wrapped in brown paper and that was certainly corrosive. Probably PLA (Chicom Army) ammo.

It was reasonably accurate and reliable in my M1A, but nothing else.

I still have a case left.  Good for plinking, and it is easy to clean with hot soapy water.

Guys,  M&P 15 in 5.45X39 shooting Russian surplus.  Sorry, should have mentioned that.

That is one sweet shooting carbine.  2 MOA out to 300 yds. (farthest I've shot it on paper) with the Russian stuff.  I should shoot it more.

The Chinese 223 ammo is brass cased and has a head stamp of CJ. It is corrosive, at least the ones I shot were.

The Chinese copper washed 7.62x51 is corrosive. I still have 3 cases of it left from long ago when it was $130 or $140 per 1000, delivered.

My 2 FALs shoot it fine.