Thanks for your reply. You gave me another idea for a solution.   19 :  1 will cause a block update. 2 will send the change to clients. 16 will prevent neighbor reactions (e.g. fences connecting, observers pulsing). That what I found in Minecraft source for "setBlockState" Function. 🤨    

all i has in it is  package com.vicken.mod3.entities.projectiles; import com.vicken.mod3.util.RegistryHandler; import net.minecraft.block.BlockState; import net.minecraft.block.Blocks; import net.minecraft.block.WallTorchBlock; import net.minecraft.entity.LivingEntity; import net.minecraft.entity.item.ItemEntity; import net.minecraft.entity.projectile.ArrowEntity; import net.minecraft.item.ItemStack; import net.minecraft.item.Items; import net.minecraft.potion.EffectInstance; import net.minecraft.potion.Effects; import net.minecraft.util.Direction; import net.minecraft.util.math.BlockPos; import net.minecraft.util.math.BlockRayTraceResult; import net.minecraft.util.math.RayTraceResult; import net.minecraft.world.World; public class Ak47ArrowEntity extends ArrowEntity { public Ak47ArrowEntity(World worldIn, LivingEntity shooter) { super(worldIn, shooter); RegistryHandler.BULLET.get(); } @Override protected void arrowHit(LivingEntity living) { super.arrowHit(living); living.setFire(15); } }

ok can u help write the code? i started learning to mod a few weeks ago all i know is items armors block recipes and other stuff. also I already have a projectile class named Ak47ArrowEntity

You have to create a new bullet entity class but you can use the snowball as a template. In kinematics there's not much difference between a snowball and a bullet. If it looks and hurts like a bullet then it's a bullet. But you have to register it as a new entity.

That is something I hadn't considered in terms of threads.   I have the WorldTickEvent handler do nothing on the client but run on the server. I may have some paths for the addEntry running on both the client and server. Something I need to look into and check if that is where the conflict is coming from.   Thanks.