Several guns, one target
Battery Fire Calculator for Arma Reforger
When a squad runs two or more guns, every gun needs its own numbers: the guns stand in different places, so range, azimuth and time of flight differ even on the same target. Reforger FDC computes a battery of up to eight guns at once and tells each crew when to fire so the rounds land together.
What the battery mode gives
- Guns
- two to eight; gun 1 is the ordinary form, the rest are added as a list
- Shared
- target, weapon, projectile and wind
- Per gun
- aim point, azimuth, elevation, operator setting and time of flight
- Sheaf
- converged, parallel, or open along the front with a set interval
- Timing
- who fires first and how many seconds each other gun waits
- Charge
- one common setting where the whole battery can share it
- Workflows
- on the map, where guns are placed and dragged, and from coordinates
- Not yet
- correcting a battery after the first volley
Three kinds of sheaf
- Converged: every gun aims at the same point. The densest strike on a small target.
- Parallel: the bursts repeat the layout of the guns. Each gun aims as far from the target as it stands from the centre of the battery, so the pattern on the ground is the pattern of the position.
- Open along the front: the bursts lie in a line across the line of fire at the interval you set, centred on the target. The leftmost gun gets the leftmost point, so crews do not fire across each other.
How the fire delays work
Each gun's firing data comes from the same single-gun calculation run from its own position to its own aim point, heights included. Then the battery is timed: the gun with the longest flight fires first, and every other gun waits the difference. Guns with equal delay share a turn, so no crew waits for a command that never comes.
The longest flight is not always the farthest gun. Take two M777s on charge 1, straight from the table. On the high arc a gun 3000 metres out flies 43.1 seconds and a gun 4000 metres out flies 40.2, because a steeper shot at a shorter range hangs longer in the air: the nearer gun fires first and the farther one waits 2.9 seconds. On the low arc the same two ranges fly 14.2 and 20.7 seconds, and the order reverses.
The common charge is chosen so the whole battery can dial the same setting, but a high arc is never swapped for a low one to get there. Where the guns stand on different sides of a table boundary and no single charge fits, the application says so and gives each gun its own.
On the map and in history
On the map the other guns, their aim points and the lines to them are drawn next to the first gun, and a gun is placed with a tap and moved by dragging. A battery is saved to mission history like any other calculation and opens back into its fields. It works with every weapon in the application: the vanilla M252 and 2B14 mortars, the M777 howitzer, the 2B9 Vasilek and the BM-21 Grad.
How to calculate a battery
- Open Reforger FDC, choose the map or coordinates, then the weapon and projectile.
- Switch from "One gun" to "Battery"; the gun fields above become gun 1.
- Add the other guns and place them, then place the target.
- Pick the sheaf, set the interval for an open sheaf, and calculate.
- Read each gun's line and pass on its settings and its delay.