Does anyone know if any 223 Rem ammo sold in the US was ever loaded with corrosive primers? I have a Mod 788 Rem rifle purchased new in 1981. At the time I did not reload for the 223 and purchased and fired many different brands of ammo from gun shows and shops. I gave the rifle average care just as I did my other rifles, some of which are older than the 788. About 1985 I took up reloading for the 223 and the gun has seen nothing but my reloads since. Fast forward to last year and I purchased one of the inexpensive flexible bore scopes. I examined the bores of all my rifles and found no significant problems on all but the 788. The bore on it is badly pitted and I am perplexed as to why. About the only thing that makes any sense would be if the gun was fired with corrosive ammo and not cleaned promptly. The accuracy of the gun is great but cleaning the barrel is a horrible chore.

Just a thought...
The early eighties was a tough time economically.
Perhaps it was the steel of the barrel as opposed to the primers.
Corrosive primers had been long out of favor by the 1980s.
Unless of course it was economics again...
But there was a lot of low grade steel in '80s products...

Any chance the gun saw any Norinco (China North Industries). Late '80s early '90s.

That happened to my .308 788. Bought some French made 308. Thought it was NATO, it wasn't. Shot great for several years after then suddenly shotgun patterns. Guess that french made stuff was from when France pulled out of NATO.

This is why I've always suggested that shooters clean after firing "mystery" foreign ammo with warm soapy water, ballistol and water, etc. If it doesn't have the NATO cross on the headstamp you can't be sure it's NATO spec., no matter what the guy at the shop or gun show said. Years ago there was some "military" .308 sold cheap made somewhere in South America. It was in a green box and had 308W (?) on the headstamp. At least some of it was corrosive-primed. I picked up a lot of the brass at the range to scrap and wondered how many people that shot it had ruined bores because they assumed it was noncorrosive since it was "recent manufacture".

Norinco. Some was mildly corrosive, most wasn't. Whether it was marked non-corrosive or not. Late '80s, early '90s.

It was from leaving the copper in the barrel