The Ak and suppressor was field tested in Oregon. Maybe there is some confusion about the set-up. The Vortex-2 is intended for .22 rim fire. GemTech makes, or made, other suppressors such as the Hornet (I believe that is what it is called) that was intended for 5.56 and full-auto .22. I don't know for sure if the bore diameter is the same for the .22 and 5.56 cans. I don't believe that there is a gap, due to a larger than needed bore, in the Vortex-2 suppressor that allows gas to escape.
When the AKT98 was field tested the folks who were standing around were amazed by the degree of sound reduction. One could hear the impact of the bullet striking the backstop 100 yards away. However, I will say that it might not be as quiet as one would expect it to be. The Vortex-2 was also used on a Walther P-22 pistol, and the sound seemed to be a bit quieter when using the pistol. This difference might be attributed to the fact that standard velocity ammo was used most of the time when shooting the AK and subsonic ammo was used when using the pistol.
I am not sure how practical this set up is other than showing off an evil AK and an evil suppressor. None the less, the two togethr are pure evil.