A typical round of 7.62x39mm fires a 123 grain full metal jacket bullet at a muzzle velocity of 2,300 feet per second. This results in good medium-range performance and relatively manageable levels of recoil.
Most 7.62x39mm ammo is steel cased and not reloadable. These cartridges are made in Eastern Europe by Tula, Barnaul (manfuacturer of the Bear series), and other companies and deliver reliable, inexpensive performance. Brass-cased ammo can be had from Fiocchi, PMC, Prvi Partizan, and other manufacturers; it is significantly more expensive but can be reloaded and used at ranges where steel cases are not permitted.
$399.99$0.40 per round