DIY Garage Bullet Trap vs 9MM?

DIY GARAGE BULLET TRAP vs 9MM?

Curiosity has gotten the best of me! I had to try 9mm and it stopped it! I will probably not shoot any caliber bigger than 22lr though.

* 27 gal Tote w/ 5.5 bags of rubber mulch.
* 3 bags are unopened.
* 2.5 poured over the unopened bags to fill gaps.
* Lid is zip tied to tub.

For added safety I put an expired bullet proof vest on the bottom of the tub then put the mulch on top of it.