Iron Nest Mission 1: Calibration Fire - Solutions

Worked example: Bearing, range, charge and elevation figures below come from a sample playthrough. Enemy spawns and your Iron Nest’s position vary each run — always measure on the map and follow the in-game ballistic calculator.

Mission Critical Strategy: The Anchor Point Rule

Calibration Fire looks like a formality. There is no hostile artillery, no counter-battery timer, no moving target and no way to fail the mission outright. That is exactly why it deserves attention: every technique you rehearse here is reused, under a ticking clock, by the twelve campaign missions that follow.

The mission has one real failure mode, and it is geometric rather than tactical. The map ruler must be anchored on the sharp spike at the bottom of the Iron Nest icon. The icon is a stylised turret silhouette, and only that bottom spike marks the true grid position of the battery. Anchor the ruler on the icon’s centre, on its turret ring, or on its floating label, and the entire measurement line shifts by a constant offset. You will then fire a solution that is consistently short and slightly off-line — while the arithmetic itself is flawless.

That offset is called parallax error, and it is the single most common reason a new operator’s first calibration shot misses. It also cannot be tuned out by adjusting elevation, because the error is angular and positional, not ballistic.

[!WARNING] Parallax error is invisible on the map. The ruler still reports a clean number and the in-game ballistic calculator still returns a clean elevation — both are confidently answering the wrong question. If your round lands short and wide by a similar margin, suspect the anchor point before you suspect the ammunition.

Why bearing does not change your elevation

New operators routinely assume that swinging the turret changes the arc of the shot. It does not. In Iron Nest the ballistic model separates the two axes cleanly:

• Traverse (bearing) rotates the turret horizontally. It changes where the barrel points on the compass and nothing else.
• Elevation (θ) sets the vertical angle, and is a function of target range and powder charge count only.

This is why the workflow below always finishes the map work before the gun work. Once you know the range and have chosen a charge count, the elevation is already determined — the bearing you happen to be pointing at while you crank the wheel is irrelevant. It also means the two errors are diagnosable: a shot that is off-line is a traverse problem, and a shot that is short or long is an elevation or charge problem.

Reading the teleprinter before touching the map

The mission opens with a teleprinter dispatch. Read it in full before you open the map, and note two things: the origin coordinates of Iron Nest, and the grid reference of the designated target. The dispatch is the only authoritative source for both. Operators who start drawing lines immediately, without recording the origin, frequently end up measuring from the previous mission’s position and spend the rest of the run chasing a phantom error.

Pre-Calculated Firing Solutions

Target Name	Target Grid	Turret Bearing	Target Range	Powder Charges	Elevation (θ)	Ammunition
Iron Nest (origin)	Grid H3 5.5	—	—	—	—	—
Target Alpha	Grid Q4 4.2	085.5°	8.91 km	2 Charges	53.5°	H (High Explosive)

Treat the table as a checklist, not a suggestion. Every value in it is confirmed in the mission briefing and reproducible with the in-game ballistic calculator.

Step-by-Step Operator Routine

The whole point of this mission is to build muscle memory for the 6-Step Firing Loop:

1. Read the teleprinter order completely.
2. Locate Target Alpha on the grid.
3. Calculate bearing and distance from Iron Nest.
4. Prepare powder charges and High Explosive (H) ammunition.
5. Traverse & Elevate the gun barrel.
6. Fire and confirm detonation.

Everything below is that loop, unpacked into phases.

Phase 1: Grid Measurement (No Timer)

1. Read the teleprinter dispatch. Record Iron Nest’s origin at grid H3 5.5 and Target Alpha at grid Q4 4.2.
2. Open the map ruler tool.
3. Anchor the start point on the bottom spike of the Iron Nest marker — not the centre of the icon, not the label.
4. Extend the line to the centre of Target Alpha.
5. Read back the two measured values and write them down:
   • Measured Range: 8.91 km
   • Measured Bearing: 085.5°
6. Sanity-check the bearing against the map: 085.5° places Target Alpha almost due east with a slight southern bias. If your figure lands in a visibly different quadrant, your anchor has slipped.

Phase 2: Ballistics Calculation (No Timer)

1. Take the measured range of 8.91 km to the charge table and select 2 Powder Charge Bags. This is the verified load for this range in the official tutorial.
2. Set elevation to 53.5° and confirm the exact value against the in-game ballistic calculator before you touch the gun. The calculator is authoritative; the table in this guide is a cross-check.
3. Note that no other input affects the elevation. Bearing, wind, ammunition type and target hardness are all irrelevant to the vertical angle.

Phase 3: Gun Preparation and Loading (No Timer)

1. Walk to the ammunition rack and select a standard H (High Explosive) round. Calibration Fire does not require anything exotic — no STAR, no AP, no chemical shell.
2. Retrieve 2 charge bags along with the shell. Confirm the count physically; a charge miscount is the second most common first-shot error after parallax.
3. Insert the shell into the open breech.
4. Follow it with the 2 charge bags.
5. Close and lock the breech lever. An unlocked breech is a hard stop — the gun will not fire, and in this mission the only cost is time.

Phase 4: Traverse, Elevate and Fire (No Timer)

1. Rotate the traverse wheel until the bearing indicator displays 085.5°. Converge on the value from the direction you approached from, so that any backlash in the wheel settles the same way every time.
2. Crank the elevation wheel until the inclinometer reads 53.5°.
3. Re-read both gauges once. Confirm bearing 085.5°, elevation 53.5°.
4. Pull the firing lanyard.

Phase 5: Confirm and Log (No Timer)

1. Watch the impact. The mission is complete on a direct hit on Target Alpha.
2. If the round is short and wide, return to Phase 1 and re-anchor the ruler on the bottom spike — do not simply add elevation and fire again, because you would be tuning a correct number into an incorrect one.
3. Log the successful pair of values in your own notes. 8.91 km / 2 charges / 53.5° is the baseline reference point for every later mission, and having one verified data point makes it much easier to spot a bad measurement when a campaign mission starts going wrong.

[!IMPORTANT] Operator Rule: In Calibration Fire, never rush to the lanyard. The mission is unrecoverable-proof, which makes it the only place in the campaign where you can build the loop deliberately — read, measure, calculate, load, traverse, elevate, fire. Every later mission assumes you already own that sequence; the counter-battery missions will not give you the time to learn it.