Are you burning through te expensive ammo? I ask because I use the cheapo stuff for blasting and plinking, no problem with blowing 1K in a weekend then. I keep some TAP on hand for range work or SHTF, but use it far more sparingly.
I've had good luck with the Yugo steelcase berdan primed 7.62X39mm. I bought 10 cases for around $100 each years ago. They of course do not meet your copper requirement though.
Never had a commie rifle fail with cheap ammo, in fact even my ARs consume Wolf with no FTF/FTE problems, but even Wolf is not cheap compared to iron-curtain surplus...non-corrosive my arse!