diff --git a/code/modules/codex/entries/ammunition_codex.dm b/code/modules/codex/entries/ammunition_codex.dm
index 5fcea857473..9f68ff7e330 100644
--- a/code/modules/codex/entries/ammunition_codex.dm
+++ b/code/modules/codex/entries/ammunition_codex.dm
@@ -35,6 +35,9 @@
 		if(ammo.penetration)
 			entry.mechanics_text += "Armor penetration: [ammo.penetration]<br>"
 
+		if(ammo.additional_xeno_penetration)
+			entry.mechanics_text += "Xenomorph additional armor penetration: [ammo.penetration]<br>"
+
 		if(ammo.armor_type)
 			entry.mechanics_text += "Armor type: [ammo.armor_type]<br>"
 
diff --git a/code/modules/codex/entries/magazine_codex.dm b/code/modules/codex/entries/magazine_codex.dm
index 0d44f7803f7..8b9570dead7 100644
--- a/code/modules/codex/entries/magazine_codex.dm
+++ b/code/modules/codex/entries/magazine_codex.dm
@@ -42,6 +42,9 @@
 	if(default_ammo.penetration)
 		traits += "Armor penetration: [default_ammo.penetration]<br>"
 
+	if(default_ammo.additional_xeno_penetration)
+		traits += "Xenomorph additional armor penetration: [default_ammo.additional_xeno_penetration]<br>"
+
 	if(default_ammo.sundering)
 		traits += "Sundering amount: [default_ammo.sundering]<br>"
 
diff --git a/code/modules/projectiles/ammo_datums.dm b/code/modules/projectiles/ammo_datums.dm
index 63958c4131f..ad19f085ab8 100644
--- a/code/modules/projectiles/ammo_datums.dm
+++ b/code/modules/projectiles/ammo_datums.dm
@@ -47,6 +47,8 @@ GLOBAL_LIST_INIT(no_sticky_resin, typecacheof(list(/obj/item/clothing/mask/faceh
 	var/damage_type = BRUTE
 	///How much armor it ignores before calculations take place
 	var/penetration = 0
+	///How much extra penetration applies to xeno
+	var/additional_xeno_penetration = 0
 	///The % chance it will imbed in a human
 	var/shrapnel_chance = 0
 	///How fast the projectile moves
diff --git a/code/modules/projectiles/projectile.dm b/code/modules/projectiles/projectile.dm
index 5b648820838..fee282c1b04 100644
--- a/code/modules/projectiles/projectile.dm
+++ b/code/modules/projectiles/projectile.dm
@@ -68,6 +68,8 @@
 	var/damage = 0
 	///ammo sundering value
 	var/sundering = 0
+	///How much extra penetration applies to xeno
+	var/additional_xeno_penetration = 0
 	var/accuracy = 90 //Base projectile accuracy. Can maybe be later taken from the mob if desired.
 
 	///how many damage points the projectile loses per tiles travelled
@@ -154,6 +156,7 @@
 	icon_state = ammo.icon_state
 	damage = ammo.damage + bonus_damage //Mainly for emitters.
 	penetration = ammo.penetration
+	additional_xeno_penetration = ammo.additional_xeno_penetration
 	sundering = ammo.sundering
 	scatter = ammo.scatter
 	airburst_multiplier = ammo.airburst_multiplier
@@ -902,12 +905,7 @@ So if we are on the 32th absolute pixel coordinate we are on tile 1, but if we a
 			damage *= STAGGER_DAMAGE_MULTIPLIER //Since we hate RNG, stagger reduces damage by a % instead of reducing accuracy; consider it a 'glancing' hit due to being disoriented.
 	var/original_damage = damage
 
-	//// RUTGMC EDIT
-	var/sunder_to_penetration = 0
-	if(isxeno(src))
-		sunder_to_penetration = log(proj.sundering + 1) * 10
-
-	damage = modify_by_armor(damage, proj.armor_type, proj.sundering >= 20 ? proj.penetration : (proj.penetration + sunder_to_penetration), proj.def_zone)// RUTGMC EDIT
+	damage = modify_by_armor(damage, proj.armor_type, isxeno(src) ? proj.penetration + proj.additional_xeno_penetration : proj.penetration, proj.def_zone)
 	if(damage == original_damage)
 		feedback_flags |= BULLET_FEEDBACK_PEN
 	else if(!damage)
@@ -919,8 +917,7 @@ So if we are on the 32th absolute pixel coordinate we are on tile 1, but if we a
 		if(IgniteMob())
 			feedback_flags |= (BULLET_FEEDBACK_FIRE)
 
-
-	if((proj.ammo.flags_ammo_behavior & AMMO_SUNDERING) && proj.sundering >= 20) // RUTGMC EDIT
+	if(proj.ammo.flags_ammo_behavior & AMMO_SUNDERING)
 		adjust_sunder(proj.sundering) // RUTGMC EDIT
 
 	if(stat != DEAD && ismob(proj.firer))