Hell Let Loose Vietnam Mortar Guide: Gunner, Observer and Support Explained

TL;DR

• The Mortar Squad has three roles: Gunner, Observer, and Support. All three are needed for the squad to function properly.
• The Gunner builds and fires the mortar and marks targets using a flare gun.
• The Observer turns the mortar toward the target and sets the correct elevation using the mortar calculator.
• The Support carries and drops ammo to keep the mortar firing, and can also resupply the Observer.
• Lower barrel angle = longer range. Higher barrel angle = shorter range. This is the key rule for all aiming.
• A mortar team with a good Observer lands shells within 25 meters of the target. Without one, accuracy drops to 50 meters or more.
• Never fire mortars without confirmed target coordinates. Random shelling wastes ammo and reveals your position.

What Is the Mortar Squad in Hell Let Loose Vietnam?

The Mortar Squad is Hell Let Loose Vietnam’s dedicated indirect fire unit. It replaces the traditional artillery from the original game with a more flexible, player-coordinated system. Instead of random shelling, mortar squads require real teamwork. Observers locate enemy positions and calculate firing coordinates before passing them to the Gunner. They are essentially human targeting computers.

The key advantage of mortars over traditional artillery is flexibility. You can set up anywhere on the map — behind enemy lines for surprise bombardments, behind your own lines for area denial, or anywhere in between. Use explosive rounds to disrupt armor movement and smoke rounds to cover your squad’s pushes.

The Mortar Squad is available to both the US and NVA factions. It is one of the most powerful tools in the game when coordinated correctly, and one of the most wasteful when not. If you want a full picture of how the mortar unit fits alongside all other roles, see our Hell Let Loose Vietnam all classes guide. For a look at how command structure shapes when and where mortars fire, our Commander guide covers that in detail.

The Three Mortar Squad Roles

Each role in the Mortar Squad has a specific job. None of them can cover for a missing teammate. If your squad is short a Support or Observer, your effectiveness drops sharply.

Mortar Gunner

The Gunner has the Wrench and Hammer tools required to build the mortar in an appropriate position. They are also responsible for firing the flare gun over the enemy concentration and marking the targets.

After the Observer adjusts direction and elevation based on the flare’s marked ping, the Gunner watches where the shell hits and calls corrections so the Observer can adjust direction and range for a tighter shot. The Gunner does not just fire — they observe impact and give feedback that tightens subsequent rounds onto the target.

Gunners in a Mortar team are the actual operators who must adjust the mortar and make sure it lands on targets provided by the Observer. Alongside the Supports, Gunners may also build a mortar and the surrounding mortar pit for their unit.

Mortar Observer

The Observer is the eyes on target, translating map coordinates into falling steel that breaks enemy assaults before they develop. This role demands map knowledge, patience, and crisp communication with your Gunner.

Your primary tools are the binoculars and the radio. The binoculars let you identify targets at range and mark them for your Gunner, while the radio carries your voice commands and grid coordinates.

Observers play an important role for a team as they provide crucial information for Commanders, assist their Squad Leaders by deploying offensive and defensive structures, and use flare guns and binoculars to assist Mortar Gunners with potential targets. The Observer is arguably the most technically demanding role in the entire Mortar Squad. Getting it right turns your mortar from a slow, imprecise weapon into a surgical tool.

Mortar Support

Support players assist Mortar Gunners by providing them with ammo and dropping resources to build the mortar in the first place. They can also assist Observers by providing them with resources. However, owing to limited supply, both cannot be done at the same time.

The Support keeps the mortar fed with ammo and drops the resources needed to build it in the first place. This role can also resupply Observers, but limited supplies mean it cannot do both at once. Decide with your squad at the start of the match which resupply priority to run — Observer supplies or mortar ammo — based on what the team needs most at any given moment.

How to Build the Mortar

Before you fire a single round, the Gunner and Support need to construct the mortar at a suitable position. The Gunner uses the Wrench and Hammer tools to place the mortar. The Support drops the resources needed to build it and keeps it stocked with shells throughout the match.

Position your mortar in a concealed spot away from obvious enemy sight lines. The jungle terrain in Hell Let Loose Vietnam gives you plenty of cover, but a mortar firing from the same location repeatedly will eventually be found. Relocate after hunters triangulate your muzzle flash — never saturate identical grids twice without fresh infantry confirmation.

The mortar pit should ideally be accessible to the Support for resupply runs but far enough back from the frontline that enemy infantry cannot stumble onto it. Mortar teams must coordinate with Squad Leaders via the leadership voice channel, as proximity chat does not reach the mortar position.

How to Aim the Mortar: The Full Step-by-Step Process

Aiming in Hell Let Loose Vietnam is not freeform. It follows a structured sequence. Every role plays a part.

Step 1: The Gunner Fires the Flare and Marks the Target

The Gunner carries the Wrench and Hammer tools needed to build the mortar in a suitable spot, fires the flare gun over the enemy, and marks targets. Each mark shows up as a ping with its distance attached — and that distance is the number you aim by.

Step 2: The Observer Rotates the Mortar to Face the Target

The observer’s task is to turn the mortar towards the target. The best way to ensure the direction of the mortar is to line up the vertical line of the mortar’s reticle over the enemy ping. On PC, A and D are the default buttons for changing the mortar’s direction.

Step 3: The Observer Sets the Correct Elevation Using the Calculator

Next, the Observer sets the mortar’s angle so that the shell actually falls on the enemy. This is where the Mortar Calculator comes into play. To adjust the mortar’s range, you increase or decrease the mortar angle and set it to the value that matches the target range. On PC, W and S are the default keys for adjusting the angle.

The core rule here: the elevation you set decides how far the shell travels. The relationship is inverse — a flatter barrel throws the round farther, and a steeper barrel drops it in short.

Step 4: The Support Drops a Shell Into the Tube and Fires

Have the Support drop a shell into the tube and fire. The round follows the angle and direction you set, landing at the matched distance along the reticle line.

Step 5: The Gunner Calls Corrections and the Team Adjusts

Let the Gunner watch the impact and call corrections. Adjust direction with A and D and range with W and S based on where the first shell fell, then fire again for a tighter grouping.

Mortar Calculator: Angle and Range Chart

This is the most important reference table for any Observer or Gunner. Match the target distance from the ping to the correct barrel angle. Lower angles reach farther, higher angles land closer, and the mapping between the two is fixed. Once you know the numbers, aiming becomes a quick lookup rather than guesswork.

Here are the key reference points confirmed from the game. Note that for example, a 175m ping needs 67°, and a 225m ping needs 49°. The full table gives you a consistent firing solution for every distance range you will encounter in a typical match:

• Very close range (100–125m): High elevation angles above 75°
• Close range (150–175m): ~67–72°
• Mid range (200–225m): ~49–57°
• Long range (250–300m+): Lower elevation angles below 45°

Memorise your most commonly used distances or write them down before a session. The in-game mortar calculator helps, but fast target acquisition means you should know the most common angles by reflex.

Important note on terrain: These angles assume flat ground. If there is significant elevation difference between your mortar position and the target, you will need to adjust. Higher targets require slightly less elevation; lower targets require slightly more. Communicate terrain differences to your Observer before the first shot.

Correction Calls: How the Observer and Gunner Talk to Each Other

Good correction calls are what separate an effective mortar team from a useless one. If the round lands 50 meters short and 20 meters left, you say “add 50, right 20” and the Gunner adjusts the tube accordingly. Each correction cycle tightens the spread until you are dropping shells directly on the enemy position.

Call grids as six-digit coordinates (100m precision) for suppression, but upgrade to eight-digit (10m precision) for confirmed kills on pinned enemy squads. A suppression mission does not need the same accuracy as an elimination mission. Use the right precision for the right task.

The Bracketing Technique

Bracketing is a technique that experienced Observers use to find the target faster. Instead of walking fire in small increments, you deliberately overshoot and undershoot the target, establishing a bracket that contains the enemy position. Once you have the bracket, you split the difference and land shells in the centre. This method gets rounds on target in two or three adjustments instead of six or seven.

Accounting for Shell Travel Time

The shell travel time creates a delay between your callout and the impact. At maximum range, mortars can take several seconds to land, which means you must lead moving targets. If an enemy squad is crossing open ground, aim where they will be when the shell arrives, not where they are now.

What to Target: Mortar Priority List

The mortar is not for shooting at individual soldiers. Every round costs your Support ammo and risks revealing your position. Spend them on targets that change the match.

1. Enemy Garrisons and Outposts

When a Recon team spots a garrison or outpost being built, they radio you the grid, and you drop shells before the spawn point becomes operational. This coordination turns your mortar from a reactive weapon into a proactive one. Destroying a garrison before it is finished denies the enemy a spawn point for the rest of the match.

2. NVA Tunnel Entrances (US Mortar Teams)

Since tunnels allow rapid troop redeployment underground, a mortar observer must track tunnel entrances and call fire missions preemptively on likely exit points rather than reacting to visible movement. A confirmed tunnel exit targeted early can strand an entire NVA squad that has just spent supplies building it.

3. Pinned Enemy Squads

When your Squad Leader reports that an infantry squad is bogged down against a fixed enemy position, mortar fire on that position creates the suppression window they need to manoeuvre around it. A well-coordinated mortar barrage followed by an infantry assault is the most reliable way to break a prepared defense.

4. Open Ground Crossing Zones

Sustained mortar fire on a crossing zone — a runway, a rice paddy, a river ford — forces enemy infantry to take cover or detour. In a Warfare match, a US mortar squad fired 12 rounds over 90 seconds to suppress an NVA tunnel exit, forcing the defenders to relocate and opening a 40-second window for infantry capture. Time your barrage to align with a friendly push.

5. Smoke Rounds for Friendly Advances

Not every mortar round needs to be explosive. A mortar smoke round from a team positioned behind a ridgeline can cover a wider crossing zone than infantry-thrown smoke. Coordinate with Squad Leaders and the Commander to time smoke barrages with your team’s advance on objectives.

Mortar Positioning: Where to Set Up

The mortar is a static weapon once built. Choosing the right position before you start construction is one of the most important decisions the Mortar Squad makes.

Cover and Concealment

Set up behind ridgelines, inside jungle cover, or in buildings where the mortar tube is not visible to enemy infantry. A mortar position that gets spotted and overrun costs the whole team, not just your squad.

Distance From the Frontline

Too close and you risk infantry engagement. Too far and your maximum range may not reach the targets your Observer is calling. On dense jungle maps, prioritise the binoculars and a compact secondary weapon. For river-network maps, equip smoke grenades to conceal your position when patrol boats pass nearby, as the sound of mortar tubes firing carries far over water.

Relocate After Firing

Never saturate identical grids twice without fresh infantry confirmation. Relocate after hunters triangulate your muzzle flash. A mortar team that stays in the same position too long will be targeted by enemy mortars, Recon units, or the Commander’s precision strike. Move regularly, even if it means rebuilding in a new spot.

How Mortars Work With the Rest of the Team

A mortar squad operating in isolation is wasting half its potential. The full value comes from integration with Recon, infantry, and the Commander.

Recon Feeds Your Targets

Recon squads are your best friends on the battlefield. Their scouts can mark enemy positions from behind lines, feeding you coordinates for targets that infantry cannot see. When a Recon team spots a garrison or outpost being built, they radio you the grid, and you drop shells before the spawn point becomes operational. Coordinate directly with your Recon squad from the start of the match and establish a communication routine. For a full breakdown of how Recon operates, read our Hell Let Loose Vietnam Sniper guide.

Infantry Squad Leaders Call Corrections

Infantry Squad Leaders also feed you valuable targeting data. When a squad is pinned down by an enemy machine gun position, the Squad Leader calls out the grid, and you suppress the position while they manoeuvre. Keep the leadership voice channel open and respond to calls quickly. A two-minute delay on a correction call is useless. To understand what Squad Leaders need from you, read our Squad Leader guide.

Helicopter Pilots Mask Your Position (US Teams)

Layer distraction audio from helicopters so headsets cannot pick out lone tube chatter. When a helicopter is operating in your area, your mortar firing is harder for the enemy to isolate acoustically. Coordinate with your Pilot if the opportunity allows. Our Hell Let Loose Vietnam Helicopter Pilot guide covers how to work with the Helicopter unit from the air side.

Commander Uses Your Intel

The Observer feeds intelligence upward too. If your Observer spots a cluster of enemy activity, that information is valuable to the Commander for calling in a Precision Strike or adjusting the team’s push direction. Keep the Commander informed of what you see, not just what you are firing at.

Mortar Tips That Actually Change Outcomes

Always Wait for a Confirmed Target

Random fire wastes ammo, reveals your position, and contributes nothing to the match. Confirm targets and friendly positions before requesting fire. Every round should have a purpose.

Check Friendly Positions Before You Fire

Mortars can affect areas far from the crew’s position, which makes bad information dangerous. The Spotter and Gunner should confirm the target and check where friendly squads are moving before each series of shots. Friendly fire from a mortar is one of the most demoralising things that can happen to a squad. Check the map before every volley.

Use Smoke Before You Use HE on Crossings

On maps with open crossing zones, lead with smoke rounds to blind the defenders before your team moves. Then switch to explosive rounds once your infantry is across and in contact. This sequencing saves lives that a straight HE barrage would waste.

Pre-Register Known Enemy Positions

Before the first contact, your Observer should identify likely enemy garrison spots, tunnel locations, and machine gun positions based on map knowledge. Fire a ranging round early and lock in that firing solution. When the call comes in during a push, you can respond in seconds instead of spending three minutes adjusting.

Never Stay Silent After a Miss

If the first round misses, the Gunner must call the correction immediately. A silent miss means the Observer cannot adjust, which means the next round is another guess. Communication is constant and immediate. Each correction cycle tightens the spread until you are dropping shells directly on the enemy position.

Mortar on Specific Maps

The mortar squad has different levels of impact depending on which map you are on. Open terrain gives you the most influence.

Dak To Airfield is the clearest mortar map in the launch lineup. Establish the Mortar squad in concealed jungle terrain behind the ridgeline with the Observer positioned at an elevated jungle edge location with line of sight over the runway crossing zone. The Observer calls targets, the Mortar squad fires, and the runway becomes impassable without smoke. Read our full Dak To Airfield guide for exact mortar positioning.

Quang Ngai has flooded lowland crossings where mortar smoke is especially valuable. A mortar smoke round from a team positioned behind a ridgeline can cover a wider crossing zone than infantry-thrown smoke. See our Quang Ngai guide for more detail.

Other maps with good mortar application include Thanh Hoa Bridge, Hue Outskirts, Van Tuong, and Cam Ranh Port. For a full map overview, see our all maps guide.

Common Mortar Mistakes to Avoid

• Firing without a marked target. Blind shelling alerts the enemy to your position and wastes ammo. Always wait for a flare mark or a grid callout from infantry.
• Ignoring corrections. If the first round misses and nobody calls a correction, the second round will miss too. The Gunner must watch every impact and report immediately.
• Staying in the same position too long. Your tube makes noise. The enemy will track it. Move regularly.
• Firing on friendly positions. Check the map. Every time. A mortar strike on a friendly squad in the middle of a push can cost the entire objective.
• Treating the Support as a passive role. Support players assist Mortar Gunners by providing ammo and dropping resources to build the mortar. They can also assist Observers by providing them with resources. A Support who is not actively resupplying is a Support wasting their slot.
• Using HE rounds when smoke is what the team needs. Know the difference. Explosive rounds kill. Smoke rounds create movement windows. Both matter. Ask your Squad Leader which one they need before you fire.

Is the Mortar Good for Beginners?

No. The Mortar Squad is one of the most coordination-heavy units in Hell Let Loose Vietnam. All three roles depend on precise communication, map knowledge, and understanding of when to fire and when not to. A new player who takes the Gunner or Observer role without the necessary experience will either fire blind or be unable to provide the corrections needed for accurate fire.

Learn the game as a Rifleman first. Understand how squads communicate and how objectives work. Once you can follow leadership channel comms and read a grid reference confidently, the Mortar Squad becomes one of the most rewarding units to play. For the right starting point, check our best class for beginners guide and our beginners guide.

Where to Get Hell Let Loose Vietnam

Hell Let Loose Vietnam is available on PlayStation Store, Xbox, and through the official site for PC.

Final Thoughts on the Hell Let Loose Vietnam Mortar Squad

The Mortar Squad is silent when it works perfectly. You will not see the kills. You will not hear the thanks. You will watch a corridor that was impassable suddenly get crossed, a garrison that was about to go up get shelled into oblivion, and a push that was stalling break through. That is what good mortar play looks like from the inside.

Learn the mortar calculator. Master the correction call sequence. Talk to your Recon squad before the match even starts. Keep your Support fed and your position moving. Do those four things consistently and the Mortar Squad becomes one of the most impactful units on the entire server — even if no one at the end of the match knows exactly why the enemy’s defence collapsed.