adds the sounds and the code

code/modules/projectiles/guns/lever_action.dm

@@ -373,6 +373,7 @@ their unique feature is that a direct hit will buff your damage and firerate
 	hit_buff_reset_cooldown = 2 SECONDS //how much time after a direct hit until streaks reset
 	var/floating_penetration = FLOATING_PENETRATION_TIER_0 //holder var
 	var/floating_penetration_upper_limit = FLOATING_PENETRATION_TIER_4
+	var/direct_hit_sound = 'sound/weapons/gun_xm88_directhit_low.ogg'
 	attachable_allowed = list(
 		/obj/item/attachable/bayonet/upp, // Barrel
 		/obj/item/attachable/bayonet,
@@ -499,12 +500,16 @@ their unique feature is that a direct hit will buff your damage and firerate
 		switch(floating_penetration)
 			if(FLOATING_PENETRATION_TIER_1)
 				P.ammo = GLOB.ammo_list[/datum/ammo/bullet/lever_action/xm88/pen20]
+				direct_hit_sound = "sound/weapons/gun_xm88_directhit_low.ogg"
 			if(FLOATING_PENETRATION_TIER_2)
 				P.ammo = GLOB.ammo_list[/datum/ammo/bullet/lever_action/xm88/pen30]
+				direct_hit_sound = "sound/weapons/gun_xm88_directhit_medium.ogg"
 			if(FLOATING_PENETRATION_TIER_3)
 				P.ammo = GLOB.ammo_list[/datum/ammo/bullet/lever_action/xm88/pen40]
+				direct_hit_sound = "sound/weapons/gun_xm88_directhit_medium.ogg"
 			if(FLOATING_PENETRATION_TIER_4)
 				P.ammo = GLOB.ammo_list[/datum/ammo/bullet/lever_action/xm88/pen50]
+				direct_hit_sound = "sound/weapons/gun_xm88_directhit_high.ogg"
 	return ..()
 
 /obj/item/weapon/gun/lever_action/xm88/unload(mob/user)
@@ -524,6 +529,7 @@ their unique feature is that a direct hit will buff your damage and firerate
 	lever_message = initial(lever_message)
 	wield_delay = initial(wield_delay)
 	cur_onehand_chance = initial(cur_onehand_chance)
+	direct_hit_sound = "sound/weapons/gun_xm88_directhit_low.ogg"
 	if(in_chamber)
 		var/obj/projectile/P = in_chamber
 		P.ammo = GLOB.ammo_list[/datum/ammo/bullet/lever_action/xm88]
@@ -536,6 +542,10 @@ their unique feature is that a direct hit will buff your damage and firerate
 	if(one_hand_lever)
 		addtimer(VARSET_CALLBACK(src, cur_onehand_chance, reset_onehand_chance), 4 SECONDS, TIMER_OVERRIDE|TIMER_UNIQUE)
 
+/obj/item/weapon/gun/lever_action/xm88/direct_hit_buff(mob/user, mob/target, one_hand_lever = FALSE)
+	. = ..()
+	playsound(target, direct_hit_sound, 75, vary = TRUE)
+
 #undef FLOATING_PENETRATION_TIER_0
 #undef FLOATING_PENETRATION_TIER_1
 #undef FLOATING_PENETRATION_TIER_2