diff --git a/core/src/mindustry/entities/bullet/BulletType.java b/core/src/mindustry/entities/bullet/BulletType.java
index ff7f9062000d..87971f02701a 100644
--- a/core/src/mindustry/entities/bullet/BulletType.java
+++ b/core/src/mindustry/entities/bullet/BulletType.java
@@ -362,7 +362,7 @@ public boolean heals(){
     }
 
     public boolean testCollision(Bullet bullet, Building tile){
-        return !heals() || bullet.team.canDamage(bullet.team) || tile.healthf() < 1f;
+        return !heals() || bullet.team.canDamage(tile.team) || tile.healthf() < 1f;
     }
 
     /** If direct is false, this is an indirect hit and the tile was already damaged.
diff --git a/core/src/mindustry/game/Team.java b/core/src/mindustry/game/Team.java
index defc80d66222..8a828285559b 100644
--- a/core/src/mindustry/game/Team.java
+++ b/core/src/mindustry/game/Team.java
@@ -50,6 +50,11 @@ public class Team implements Comparable<Team>{
             new Team(i, "team#" + i, Color.HSVtoRGB(360f * Mathf.random(), 100f * Mathf.random(0.4f, 1f), 100f * Mathf.random(0.6f, 1f), 1f));
         }
         Mathf.rand.setSeed(new Rand().nextLong());
+        //weakly initialize team flags
+        for(int i = 0; i < 256; i++){
+            all[i].flags[0] = TeamFlags.derelictTarget;
+            all[i].flags[i] = TeamFlags.genericSelf;
+        }
     }
 
     public static Team get(int id){
@@ -126,13 +131,23 @@ public boolean needsFlowField(){
         return isAI() && !rules().rtsAi;
     }
 
-    /** flag bindings */
+    /** Reset all flags to their default values. **/
+    public void initializeFlags(){
+        for(int i = 0; i < 256; i++){
+            for(int j = 1; j < 256; j++){
+                all[i].flags[j] = TeamFlags.genericEnemy;
+            }
+            all[i].flags[0] = TeamFlags.derelictTarget;
+            all[i].flags[i] = TeamFlags.genericSelf;
+        }
+    }
+
+    /** Flag binding methods. */
     public boolean isEnemy(Team other){
         if(other == null) return false;
         return (this.flags[other.id] & TeamFlags.isNeutral) == 0;
     }
 
-    /** used for rendering */
     public boolean isAlly(Team other){
         if(other == null) return false;
         return (this.flags[other.id] & TeamFlags.allyCheck) == TeamFlags.allyCheck;
diff --git a/core/src/mindustry/game/Teams.java b/core/src/mindustry/game/Teams.java
index c9767f6613db..38c81590b3f5 100644
--- a/core/src/mindustry/game/Teams.java
+++ b/core/src/mindustry/game/Teams.java
@@ -55,6 +55,7 @@ public CoreBuild closestCore(float x, float y, Team team){
         return Geometry.findClosest(x, y, get(team).cores);
     }
 
+    //possibly deprecate: formerly only used in Build
     public boolean anyEnemyCoresWithin(Team team, float x, float y, float radius){
         for(TeamData data : active){
             if(team.isEnemy(data.team)){
@@ -68,6 +69,20 @@ public boolean anyEnemyCoresWithin(Team team, float x, float y, float radius){
         return false;
     }
 
+    public boolean anyRadiusCoresWithin(Team team, float x, float y, float radius){
+        for(TeamData data : active){
+            if(!team.ignoresBuildRadius(data.team)){
+                for(CoreBuild tile : data.cores){
+                    if(tile.within(x, y, radius)){
+                        return true;
+                    }
+                }
+            }
+        }
+        return false;
+    }
+
+    //possibly deprecate: formerly only used in OverlayRenderer
     public void eachEnemyCore(Team team, Cons<Building> ret){
         for(TeamData data : active){
             if(team.isEnemy(data.team)){
@@ -78,6 +93,16 @@ public void eachEnemyCore(Team team, Cons<Building> ret){
         }
     }
 
+    public void eachRadiusCore(Team team, Cons<Building> ret){
+        for(TeamData data : active){
+            if(team.ignoresBuildRadius(data.team)){
+                for(Building tile : data.cores){
+                    ret.get(tile);
+                }
+            }
+        }
+    }
+
     /** Returns team data by type. */
     public TeamData get(Team team){
         return map[team.id] == null ? (map[team.id] = new TeamData(team)) : map[team.id];
diff --git a/core/src/mindustry/graphics/OverlayRenderer.java b/core/src/mindustry/graphics/OverlayRenderer.java
index 1e360c3af2d9..24b290ea01a7 100644
--- a/core/src/mindustry/graphics/OverlayRenderer.java
+++ b/core/src/mindustry/graphics/OverlayRenderer.java
@@ -182,7 +182,7 @@ public void drawTop(){
 
                 Draw.color();
             }else{
-                state.teams.eachEnemyCore(player.team(), core -> {
+                state.teams.eachRadiusCore(player.team(), core -> {
                     //it must be clear that there is a core here.
                     if(/*core.wasVisible && */Core.camera.bounds(Tmp.r1).overlaps(Tmp.r2.setCentered(core.x, core.y, state.rules.enemyCoreBuildRadius * 2f))){
                         Draw.color(Color.darkGray);