7.62x39 Bullets

7.62x39 bullets are .309 to .311 diameter according to SAAMI, and .312 diameter according to the CIP. Bullets weighing 123 grains are popular for reloading as they will let you reliably replicate the ballistic performance of the original Soviet M43 cartridge. Bullets weighing 125 grains or 150 grains are commonly used for reloading as well, and have an abundance of loading data available online.

One difficulty the 7.62x39 presents to reloaders is its case, which is commonly made of steel. It is possible to reload steel, but its lack of elasticity makes it pretty much not worthwhile. To make matters worse a steel casing is commonly accompanied by a Berdan primer, which utilizes two flash holes and presents a whole other set of challenges. You could theoretically repurpose 220 Swift or 220 Russian cases, but doing so would prove far less economical than simply buying new cases made specifically for 7.62x39. Your best bet is to buy factory loaded 7.62x39 with brass cases from manufacturers like Prvi Partizan, Sellier & Bellot, or Federal and simply pick up what your AK spits out.