diff --git a/restoration/source410/BT/EMITTER.CPP b/restoration/source410/BT/EMITTER.CPP
index 70484296..a22b6d73 100644
--- a/restoration/source410/BT/EMITTER.CPP
+++ b/restoration/source410/BT/EMITTER.CPP
@@ -190,6 +190,29 @@ void
 	//
 	PoweredSubsystem::PoweredSubsystemSimulation(time_slice);
 
+	//
+	// Hard failure (@4baab9): weapon DESTROYED or its own sink at FailureHeat
+	// -> drop the beam state and the charge, and hold there.  Unlike the
+	// ballistic roach-motel this recovers by itself: once conduction cools the
+	// sink below the failure threshold the gate stops firing and the weapon
+	// resumes from Loading.  (The owning-mech-disabled half joins with the
+	// damage wave.)
+	//
+	if (GetSimulationState() == 1 || GetHeatState() == FailureHeat)
+	{
+		if (getenv("BT_MECH_LOG") && GetWeaponState() != LoadingState)
+		{
+			DEBUG_STREAM << "[fire] '" << GetName()
+				<< "' THERMAL SHUTDOWN (T=" << CurrentTemperatureOf()
+				<< ")" << endl << flush;
+		}
+		ResetFiringState();
+		chargeLevel = 0.0f;
+		ComputeOutputVoltage();
+		Check_Fpu();
+		return;
+	}
+
 	{
 		static int forceFire = -1;
 		if (forceFire < 0)
diff --git a/restoration/source410/BT/HEAT.NOTES.md b/restoration/source410/BT/HEAT.NOTES.md
index 1afcb523..e05f93b3 100644
--- a/restoration/source410/BT/HEAT.NOTES.md
+++ b/restoration/source410/BT/HEAT.NOTES.md
@@ -81,9 +81,30 @@ threshold: the authentic fire-discipline game.  SRM salvos spike +641K and
 cross degradation after three.  Condensers absorb and pass to the central
 bank.  Neutral run: sensor Ready/100%, mech holds, zero Fail.
 
+## Heat consequences (Phase 5.3.11, 2026-07-22)
+
+The weapon-side consequences are wired and VERIFIED under sustained fire:
+
+- **Ballistic gate 1** (@4bbd36): weapon destroyed-state or its own sink at
+  FailureHeat pins full recoil + the unavailable alarm (the NoAmmo roach-motel
+  re-asserts).  (Mech-disabled half joins the damage wave.)
+- **CheckForJam** (@4bbfcc): `p = 0.41·T/failT` clamped [minJamChance, 1.0],
+  rolled per granted shot against the MUNGA uniform `Random`.  Interim gate:
+  heat-degraded only (stands in for the deferred `LiveFireEnabled` novice
+  switch AND the trivially-true `heatLoad>0` early-out — the exact spurious-
+  cold-jam trap the BT411 port documented).  Verified: SRM6s jam at
+  T≈1200-1320 (24%+ rolls past the 1000° threshold), stay jammed.
+- **Emitter hard gate** (@4baab9): FailureHeat drops the beam state + charge
+  each frame; SELF-RECOVERING — conduction cools the sink below 2000° and the
+  weapon resumes from Loading.  Verified: the PPC settles into an emergent
+  thermal duty cycle (fire at ~1930° → spike 2562° → shutdown → cool → refire);
+  the lasers oscillate around ~2200°.
+
 ## Still deferred
 
-UpdateCoolant / BalanceCoolant (coolant depletion + venting), the HeatModelOff
-experience gate (novice mode), the electrical charge model (TrackSeekVoltage /
-voltage sag / I²R), gate 1 + the heat-scaled jam roll in the weapon FSMs, the
-central sink's forward-linked drain, Condenser MoveValve handling.
+UpdateCoolant / BalanceCoolant (coolant depletion + venting), the
+HeatModelOff / LiveFireEnabled experience gates (novice mode), the electrical
+charge model (TrackSeekVoltage / voltage sag / I²R), the mech-disabled halves
+of the weapon gates (damage wave), the central sink's forward-linked drain,
+Condenser MoveValve handling, jam recovery via ResetToInitialState (mission
+reset path).
diff --git a/restoration/source410/BT/PROJWEAP.CPP b/restoration/source410/BT/PROJWEAP.CPP
index 0bde9cca..31736b21 100644
--- a/restoration/source410/BT/PROJWEAP.CPP
+++ b/restoration/source410/BT/PROJWEAP.CPP
@@ -23,6 +23,10 @@
 #	include <ammobin.hpp>
 #endif
 
+#if !defined(RANDOM_HPP)
+#	include <random.hpp>
+#endif
+
 Derivation
 	ProjectileWeapon::ClassDerivations(
 		MechWeapon::ClassDerivations,
@@ -159,6 +163,48 @@ void
 	}
 }
 
+//
+//#############################################################################
+// CheckForJam -- the heat-scaled jam roll (binary @4bbfcc):
+//     p = 0.41 * currentTemperature / failureTemperature,
+//     clamped to [minJamChance, 1.0], rolled against a uniform random.
+// A jammed launcher clears only on ResetToInitialState (mission reset).
+//
+// TWO interim gates stand in for deferred systems (the BT411 port hit exactly
+// this): the authentic leading gate is LiveFireEnabled() -- the player
+// experience switch (novice mode = no jams), which needs the player-link
+// accessor wave -- and the binary's own `heatLoad <= 0` early-out is trivially
+// true once the heat model runs.  Until LiveFireEnabled lands, gate the roll
+// on the sink actually being heat-degraded, so cold weapons fire reliably and
+// jams appear exactly when the heat economy says the weapon is cooking.
+//#############################################################################
+//
+Logical
+	ProjectileWeapon::CheckForJam()
+{
+	Check(this);
+
+	if (GetHeatState() < DegradationHeat)		// interim LiveFireEnabled stand-in
+	{
+		return False;
+	}
+
+	Scalar p = (0.41f * CurrentTemperatureOf()) / failureTemperature;
+	if (minJamChance <= p)
+	{
+		if (p > 1.0f)
+		{
+			p = 1.0f;
+		}
+	}
+	else
+	{
+		p = minJamChance;
+	}
+
+	return (p > (Scalar)Random) ? True : False;
+}
+
 //
 //#############################################################################
 // ProjectileWeaponSimulation  The ballistic per-frame fire state machine
@@ -209,6 +255,24 @@ void
 	//
 	Logical trigger = CheckFireEdge();
 
+	//
+	// Gate 1 (@4bbd36): weapon DESTROYED or its own sink at FailureHeat -> pin
+	// full recoil + the unavailable alarm.  No return -- the frame continues
+	// into the state machine (whose NoAmmo case re-asserts).  (The owning-mech-
+	// disabled half joins with the damage wave.)
+	//
+	if (GetSimulationState() == 1 || GetHeatState() == FailureHeat)
+	{
+		if (getenv("BT_MECH_LOG") && GetWeaponState() != NoAmmoState)
+		{
+			DEBUG_STREAM << "[fire] '" << GetName()
+				<< "' -> UNAVAILABLE (gate1: heatState=" << GetHeatState()
+				<< " T=" << CurrentTemperatureOf() << ")" << endl << flush;
+		}
+		recoil = rechargeRate;
+		weaponAlarm.SetLevel(NoAmmoState);
+	}
+
 	//
 	// Gate 2: the linked AmmoBin.  Empty (or missing) -> pin unavailable EVERY
 	// frame while dry.
@@ -244,6 +308,16 @@ void
 					{
 						weaponAlarm.SetLevel(NoAmmoState);
 					}
+					else if (CheckForJam())
+					{
+						weaponAlarm.SetLevel(JammedState);
+						if (getenv("BT_MECH_LOG"))
+						{
+							DEBUG_STREAM << "[fire] '" << GetName()
+								<< "' JAMMED (T=" << CurrentTemperatureOf()
+								<< ")" << endl << flush;
+						}
+					}
 					else
 					{
 						weaponAlarm.SetLevel(LoadingState);
diff --git a/restoration/source410/BT/PROJWEAP.HPP b/restoration/source410/BT/PROJWEAP.HPP
index 7b005eb5..f4f495e0 100644
--- a/restoration/source410/BT/PROJWEAP.HPP
+++ b/restoration/source410/BT/PROJWEAP.HPP
@@ -77,6 +77,8 @@
 
 		void
 			ProjectileWeaponSimulation(Scalar time_slice);
+		Logical
+			CheckForJam();
 
 	public:
 		typedef ProjectileWeapon__SubsystemResource SubsystemResource;