diff --git a/code/datums/ammo/bullet/special_ammo.dm b/code/datums/ammo/bullet/special_ammo.dm
index cdf30b1af7fe..3d53c6b0c0d0 100644
--- a/code/datums/ammo/bullet/special_ammo.dm
+++ b/code/datums/ammo/bullet/special_ammo.dm
@@ -108,6 +108,9 @@
 		BULLET_TRAIT_ENTRY(/datum/element/bullet_trait_iff)
 	))
 
+/datum/ammo/bullet/machinegun/doorgun
+	flags_ammo_behavior = AMMO_BALLISTIC | AMMO_IGNORE_COVER
+
 /datum/ammo/bullet/machinegun/auto // for M2C, automatic variant for M56D, stats for bullet should always be moderately overtuned to fulfill its ultra-offense + flank-push purpose
 	name = "heavy machinegun bullet"
 
diff --git a/code/modules/cm_marines/smartgun_mount.dm b/code/modules/cm_marines/smartgun_mount.dm
index 01183ebceca5..9cad7583d8d8 100644
--- a/code/modules/cm_marines/smartgun_mount.dm
+++ b/code/modules/cm_marines/smartgun_mount.dm
@@ -1080,6 +1080,7 @@
 	projectile_coverage = PROJECTILE_COVERAGE_HIGH
 	icon = 'icons/turf/whiskeyoutpost.dmi'
 	zoom = 1
+	ammo = /datum/ammo/bullet/machinegun/doorgun
 
 /obj/structure/machinery/m56d_hmg/mg_turret/dropship
 	name = "\improper scoped M56D heavy machine gun"