Back in 1970, I was shooting nazi head stamped 9MM from my Browning HP. All shot fine!
A few days later I noticed (gasp) horrible BARREL CORROSION!
Unfortunatly, they are corrosive. Your example was, not doubt a strong learning influence in your life!
I bet you did not make that mistake a second time!
It appears the non-corrosive primers were perfected enough by 1956, that they are extremely stable and reliable as well.
Yes, beware of corrosion! Probably most people interested enough to browse this know that older ammo had primers that can corrode your gun if you fire the ammo. If you are new to guns, that old surplus ammo has corrosion risks to your gun. You must thoroughly clean your gun after firing corrosive ammo. If you set it in your closet and clean it a week later when you get around to it, you might get an unpleasant surprise. I shot hundreds of rounds of such ammo in my old rifle without a problem but I cleaned it promptly after I was done.