i cant see my projectiles in multiplayer client … and the impact and the decal i can see it the server but not on client i do replicated the BP and the mesh and impact and decal variables

Have you tried with the Always Relevant flag set to true? (Its under the Replication category of the Blueprint class defaults). Additionally, you’ll need to ensure that the server is spawning the projectiles for best results. Be sure to check this tutorial (Part 1 & 2)