[Nero_3D]

fX, fY and fZ are offsets and not the target position
Anyways for the weapon pos you need GetPlayerLastShotVectors

PHP Code:

// OnPlayerWeaponShot
    if(hittype == BULLET_HIT_TYPE_PLAYER) 
    {
        new
            Float: vX,
            Float: vY,
            Float: vZ
        ;
        GetPlayerLastShotVectors(playerid, vX, vY, vZ, fX, fY, fZ);
        vX = fX - vX;
        vY = fY - vY;
        vZ = fZ - vZ;
        (Float: hittype) = 5.0 / VectorSize(vX, vY, vZ);
        vX *= Float: hittype;
        vY *= Float: hittype;
        vZ *= Float: hittype;
        if(CA_RayCastLineAngle(fX, fY, fZ, fX + vX, fY + vY, fZ + vZ, vX, vY, vZ, fX, fY, fZ))
            SetTimerEx("DestroyBlood", 1500, false, "d", CreateDynamicObject(19836, vX, vY, vZ, fX, fY, fZ));
    }