Yes, we must assume all berdan primed (non reloadable) ammo as corrosive. Maybe not, but field strip and clean everything -inside and out- after each session -anyway. I remember buying it for that price- nearly 20 years ago. There was no US made, and no ex-soviet or eastern european ammo yet, Norinco was the only game in town, and nothing wrong with it. This might be old stuff, if steel core- good for you , don't waste it, like money in the bank, You can't even handload its equal. BTW, it was the thompson contender barrel in this calibre that caused the first stir over this stuff, again in the earlly 90's...