diff --git a/code/modules/projectiles/guns/projectile/automatic.dm b/code/modules/projectiles/guns/projectile/automatic.dm
index 08cafa3a781..804e7d151ea 100644
--- a/code/modules/projectiles/guns/projectile/automatic.dm
+++ b/code/modules/projectiles/guns/projectile/automatic.dm
@@ -111,7 +111,7 @@
 
 /obj/item/weapon/gun/projectile/automatic/wt550
 	name = "security auto rifle"
-	desc = "A outdated personal defence weapon. Uses 9mm rounds and is designated the WT-550 Automatic Rifle."
+	desc = "An outdated personal defence weapon. Uses 4.6x30mm rounds and is designated the WT-550 Automatic Rifle."
 	icon_state = "wt550"
 	item_state = "arg"
 	mag_type = /obj/item/ammo_box/magazine/wt550m9