Aye pistol round and rifle round are 2 completely different ball games.
.308 rifle round will go through pretty thick steel that glass ain't gonna do ****.
As you say an AK47 which uses very similar gonna sail through that, you, the glass behind you and still go another several hundred metres before it hits something solid.
you can get glass that resists quite a few ak47 rounds before failing - its far more effective than steel