Particles and materials

Hey there! Im the beginner in using ue4, so my question can be funny for you. How to make material with form of bullet? How to use gravity and collision on them in particle system?
Sincerelly, Kirill.

I dont understand. Are you trying to make a bullet hole decal?

no, I want to make particle system, which particles are small bullets, which collides and jump off the ground, instead of tens of actors.