Its still around to an extent - just gotta know where to look, pester the right people, then pester them some more, pester them again, then keep pestering them until the guilt of being a pest wears off, then pester them some more, have money in your pocket at all times, and buy all that you see without paying more than $1 a round.
I was able to pick up about 1600 rounds of 1950s CAC stuff over the course of last year without too much trouble. Funnily enough, when it is up fro sale there doesn't tend to be too much interest as most folks these days are after 7.62x51 or 5.56x45.
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