WHAT DOES RED ARMY STANDARD 7.62×39 MEAN?

Fired flawlessly by means of my Glock. At 21ft went from ten inch groupings all the way down to 2 in groupings making use of this stuff then back to ten inch groupings immediately after I used it. Distinct as day these items is precise with pretty much NO recoil. Wouldn't want this within a tactical scenario but if you want to see how correct you t