Ouch.

code/modules/mob/living/silicon/ai/ai_defense.dm

@@ -42,9 +42,8 @@
 
 
 /mob/living/silicon/ai/bullet_act(obj/item/projectile/Proj)
-	..(Proj)
+	. = ..()
 	updatehealth()
-	return 2
 
 /mob/living/silicon/ai/flash_act(intensity = 1, override_blindness_check = 0, affect_silicon = 0)
 	return // no eyes, no flashing

code/modules/mob/living/silicon/pai/pai_defense.dm

@@ -55,7 +55,7 @@
 	if(P.stun)
 		fold_in(force = TRUE)
 		visible_message("<span class='warning'>The electrically-charged projectile disrupts [src]'s holomatrix, forcing [src] to fold in!</span>")
-	. = ..()
+	return ..()
 
 /mob/living/silicon/pai/stripPanelUnequip(obj/item/what, mob/who, where) //prevents stripping
 	to_chat(src, "<span class='warning'>Your holochassis stutters and warps intensely as you attempt to interact with the object, forcing you to cease lest the field fail.</span>")

code/modules/mob/living/silicon/robot/robot_defense.dm

@@ -184,8 +184,7 @@
 				adjustBruteLoss(30)
 
 /mob/living/silicon/robot/bullet_act(obj/item/projectile/P, def_zone)
-	..()
+	. = ..()
 	updatehealth()
 	if(prob(75) && P.damage > 0)
 		spark_system.start()
-	return 2

code/modules/mob/living/silicon/silicon_defense.dm

@@ -129,7 +129,7 @@
 			unbuckle_mob(M)
 			M.visible_message("<span class='boldwarning'>[M] is knocked off of [src] by the [P]!</span>")
 	P.on_hit(src)
-	return 2
+	return BULLET_ACT_HIT
 
 /mob/living/silicon/flash_act(intensity = 1, override_blindness_check = 0, affect_silicon = 0, visual = 0, type = /obj/screen/fullscreen/flash/static)
 	if(affect_silicon)