bullet layer and such, dont collide bullets with other bullets

Asteroid.tscn

@@ -15,7 +15,7 @@ input/pickable = false
 shapes/0/shape = SubResource( 1 )
 shapes/0/transform = Matrix32( 1, 0, 0, 1, -0.17482, 1.87222 )
 shapes/0/trigger = false
-collision/layers = 1
+collision/layers = 3
 collision/mask = 1
 collision/margin = 0.08
 script/script = ExtResource( 1 )

Bullet.gd

@@ -10,7 +10,7 @@ func _ready():
 	
 func fire(delta, vel, dir, speed):
 	velocity = (vel.length() * dir + (dir * speed * delta))
-	sprite.rotate(dir.angle())
+	sprite.set_rot(dir.angle())
 
 func type():
 	return "Bullet"

Bullet.tscn

@@ -11,11 +11,12 @@ extents = Vector2( 0.99762, 3.98857 )
 [node name="Bullet" type="KinematicBody2D"]
 
 transform/rot = 180.0
+transform/scale = Vector2( 2, 2 )
 input/pickable = false
 shapes/0/shape = SubResource( 1 )
 shapes/0/transform = Matrix32( 1, 0, 0, 1, 0, 0 )
 shapes/0/trigger = false
-collision/layers = 1
+collision/layers = 2
 collision/mask = 1
 collision/margin = 0.08
 script/script = ExtResource( 1 )

EnemyGrunt.tscn

@@ -8,7 +8,7 @@
 
 transform/scale = Vector2( 2, 2 )
 input/pickable = false
-collision/layers = 1
+collision/layers = 3
 collision/mask = 1
 collision/margin = 0.08
 script/script = ExtResource( 1 )

Gun.gd

@@ -4,7 +4,8 @@ var Bullet = load("res://Bullet.tscn")
 
 var gun_cooldown = 0
 var gun_delay = 0.1125
-var gun_spread_max = deg2rad(1) # degrees max
+var gun_spread_max = deg2rad(4) # degrees max
+var gun_bullet_speed = 384
 
 func _ready():
 	set_fixed_process(true)
@@ -19,5 +20,5 @@ func fire(delta, vel, dir):
 		new_bullet.set_pos(gun_pos + vel)
 		get_tree().get_root().add_child(new_bullet)
 		var rot = rand_range(-gun_spread_max, gun_spread_max)
-		new_bullet.fire(delta, vel, dir.rotated(rot), 512)
+		new_bullet.fire(delta, vel, dir.rotated(rot), gun_bullet_speed)
 		gun_cooldown += gun_delay

Player.tscn

@@ -10,7 +10,7 @@
 
 transform/scale = Vector2( 2, 2 )
 input/pickable = false
-collision/layers = 1
+collision/layers = 3
 collision/mask = 1
 collision/margin = 0.08
 script/script = ExtResource( 1 )

PowerStation.tscn

@@ -6,7 +6,7 @@
 [node name="PowerStation" type="KinematicBody2D"]
 
 input/pickable = false
-collision/layers = 1
+collision/layers = 3
 collision/mask = 1
 collision/margin = 0.08
 script/script = ExtResource( 1 )