@shooternz sells cast boolits.
Don't use .30 cal bullets in a 7.62x39 but rather .303 bullets. The standard rifling in an AK is said to handle heavier cast boolits well, as it has a fast twist inherited from repurposed Mosin tooling, so think beyond 150 grain. Sub loads for .303s should translate well to 7.62x39 subs as similar twist rates.
I'd try shooternz's .303 boolits before condemning the rifle to shortening.
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