diff --git a/LEGO1/lego/legoomni/include/act3ammo.h b/LEGO1/lego/legoomni/include/act3ammo.h
index 4cd23f66..379971b4 100644
--- a/LEGO1/lego/legoomni/include/act3ammo.h
+++ b/LEGO1/lego/legoomni/include/act3ammo.h
@@ -27,7 +27,7 @@ class Act3Ammo : public LegoPathActor {
 	MxU32 IsValid() { return m_ammoFlag & c_valid; }
 
 	// FUNCTION: BETA10 0x100177b0
-	Mx3DPointFloat* GetUnknown0x160() { return m_unk0x160; }
+	Mx3DPointFloat* GetUnknown0x160() { return m_eq; }
 
 	// FUNCTION: BETA10 0x100177e0
 	MxFloat* GetUnknown0x19c() { return &m_unk0x19c; }
@@ -70,11 +70,11 @@ class Act3Ammo : public LegoPathActor {
 	// Act3Ammo::`scalar deleting destructor'
 
 private:
-	MxU16 m_ammoFlag;             // 0x154
-	MxFloat m_unk0x158;           // 0x158
-	Act3* m_a3;                   // 0x15c
-	Mx3DPointFloat m_unk0x160[3]; // 0x160
-	MxFloat m_unk0x19c;           // 0x19c
+	MxU16 m_ammoFlag;       // 0x154
+	MxFloat m_unk0x158;     // 0x158
+	Act3* m_a3;             // 0x15c
+	Mx3DPointFloat m_eq[3]; // 0x160
+	MxFloat m_unk0x19c;     // 0x19c
 };
 
 #endif // ACT3AMMO_H
diff --git a/LEGO1/lego/legoomni/src/actors/act3ammo.cpp b/LEGO1/lego/legoomni/src/actors/act3ammo.cpp
index 475ed8cd..bf214ded 100644
--- a/LEGO1/lego/legoomni/src/actors/act3ammo.cpp
+++ b/LEGO1/lego/legoomni/src/actors/act3ammo.cpp
@@ -80,11 +80,39 @@ MxResult Act3Ammo::Create(Act3* p_a3, MxU32 p_isPizza, MxS32 p_index)
 	return SUCCESS;
 }
 
-// STUB: LEGO1 0x10053b40
-// STUB: BETA10 0x1001db2a
+// FUNCTION: LEGO1 0x10053b40
+// FUNCTION: BETA10 0x1001db2a
 MxResult Act3Ammo::FUN_10053b40(Vector3& p_srcLoc, Vector3& p_srcDir, Vector3& p_srcUp)
 {
-	// TODO
+	assert(p_srcDir[1] != 0);
+
+	MxFloat local1c = -(p_srcLoc[1] / p_srcDir[1]);
+	Mx3DPointFloat local18(p_srcDir);
+	Mx3DPointFloat local34;
+
+	local18 *= local1c;
+	local18 += p_srcLoc;
+
+	local34[0] = local34[2] = 0.0f;
+	local34[1] = -1.0f;
+
+	m_eq[1] = p_srcUp;
+	m_eq[2] = p_srcLoc;
+
+	Mx3DPointFloat local48(local34);
+	local48 -= m_eq[1];
+
+	for (MxS32 i = 0; i < 3; i++) {
+		if (local18[0] == p_srcLoc[0]) {
+			return FAILURE;
+		}
+
+		m_eq[0][i] = (local48[i] * local48[i] + local48[i] * m_eq[1][i] * 2.0f) / ((local18[i] - p_srcLoc[i]) * 4.0f);
+	}
+
+	assert(m_eq[0][0] > 0.000001 || m_eq[0][0] < -0.000001);
+
+	m_unk0x19c = local48[0] / (m_eq[0][0] * 2.0f);
 	return SUCCESS;
 }