Weapon_Base.Fire(mi, pos, dir, speed) native: on a server-side AI INSTANCETYPE_AI_SERVER) the ballistic projectile flies with real flight time only on the first shot; the 2nd shot's impact callback never fires, and 3rd+ shots impact instantly (0–1 ms) while still landing at the correct ~420 m endpoint.

What happened

A server-side AI bot (no client, INSTANCETYPE_AI_SERVER) fires a bolt-action Mosin9130 (7.62x54R) at a ground target ~420 m away, single shots ~2.5 s apart, reloaded between shots via WeaponManager.EjectBullet() (bolt cycle) / LoadMultiBullet (chamber-load from loose ammo in cargo).

We log GetGame().GetTime() immediately before Fire() and inside an override of DayZGame.FirearmEffects(...). Measured deltas:

| shot | `Fire()` call | `FirearmEffects` (impact) | Δ |
|---|---|---|---|
| 1 | 93282 | 93944 | **+662 ms — real flight** |
| 2 | 95782 | *(never fired)* | impact callback missing |
| 3 | 98282 | 98283 | +1 ms |
| 4+ | … | … | 0–1 ms (instant) |

Critical detail: even the "instant" impacts report the correct final position (the ground ~423 m from the muzzle: muzzle z≈10831 → impact z≈10461), with a correct inSpeed decayed by air friction. So the hit position and impact speed are right — only the flight-time simulation / scheduling is skipped after the first shot, and the 2nd shot's impact is swallowed entirely.

Reproduced across multiple runs and bots; always the same pattern: 1st real, 2nd missing, 3rd+ instant.

1. Spawn a server-side AI unit INSTANCETYPE_AI_SERVER, no client / no GetCameraPoint input) holding a bolt-action Mosin9130 + Ammo_762x54 (chambered + spare loose rounds in cargo).

2. Aim at a stationary ground target ~400 m away; keep the weapon raised and ready.

3. Fire a single shot through the low-level native with an explicit muzzle origin and aim direction (see code below) — not TryFireWeapon, because an AI never drives the internal GetCameraPoint aim:

 // origin = muzzle position, direction = normalized aim dir

   vector pos = origin + direction * 0.2;

   bool fired = Fire(muzzleIndex, pos, direction, direction); // speed arg = unit dir; magnitude from CfgAmmo initSpeed

4. Wrap DayZGame.FirearmEffects(...) in an override and log GetGame().GetTime() at both the Fire() call site and inside FirearmEffects.

5. Between shots, cycle the bolt EjectBullet) / chamber-load LoadMultiBullet) so the chamber is live again, wait ~2.5 s, fire again.

6. Repeat 3–5 several times and compare FirearmEffects arrival times.

Observed: shot 1 arrives ~660 ms later; shot 2 produces no FirearmEffects at all; shots 3+ arrive 0–1 ms after Fire().

More information

Fire path (server only):

// reg/4_World/modded_WeaponBase.c
bool dmBot_Fire(int muzzleIndex)
{
    vector origin, direction, velocity;
    pawn.ComputeShot(this, muzzleIndex, origin, direction, velocity); // muzzle pos + aim dir
    vector pos = origin + direction * 0.2;
    // timing marker:
    dmBotLog.Debug("[Ballistics] FIRE time=" + GetGame().GetTime());
    return Fire(muzzleIndex, pos, direction, velocity); // velocity == unit direction
}

Impact marker:

// core/3_Game/modded/modded_DayZGame.c
modded class DayZGame
{
    override void FirearmEffects(Object source, Object directHit, int componentIndex,
        string surface, vector pos, vector surfNormal, vector exitPos,
        vector inSpeed, vector outSpeed, bool isWater, bool deflected, string ammoType)
    {
        super.FirearmEffects(...);
        dmBotLog.Debug("[Ballistics] IMPACT time=" + GetGame().GetTime()
            + " pos=" + pos + " inSpeed=" + inSpeed);
    }
}

Log evidence (abridged)

08:30:16 [Ballistics] FIRE time=93282  origin=<4130.03,340.46,10831.08> dir=<0.486,-0.000,-0.873>
08:30:16 [Ballistics] IMPACT time=93944 pos=<4335.62,338.28,10461.24> inSpeed=<254,-5,-458>   ← +662 ms
08:30:18 [Ballistics] FIRE time=95782  origin=<4130.03,340.46,10831.08>                       ← no IMPACT follows
08:30:21 [Ballistics] FIRE time=98282  origin=<4130.03,340.46,10831.08>
08:30:21 [Ballistics] IMPACT time=98283 pos=<4335.04,338.27,10463.39> inSpeed=<255,-5,-459>   ← +1 ms

- A related vanilla timing bug is referenced in the DayZ-Expansion source as T186177 ("firing over a longer distance … to ensure the projectile is in flight for a certain amount of time"); Expansion AI does not trust the Fire() native's timing/entity — it does its own hitscan, records the shot, and defers ProcessDirectDamage via CallLater to re-create the travel time in script.

- Separate (same area, different symptom): Fire() does not mark the chamber IsChamberFiredOut (chamber stays "loaded" after Fire()), so the weapon FSM re-syncs to a wrong state — reported separately.

You could check it with my mod: https://steamcommunity.com/sharedfiles/filedetails/?id=3796005638

just type in chat: /test bot flytime 400

Every shot should spawn a real ballistic projectile that flies for the physical travel time (at 400 m with initSpeed ≈ 830 and airFriction ≈ -0.0009..-0.001, roughly 550–700 ms), with FirearmEffects firing once per shot at the actual arrival moment and inSpeed reflecting the air-friction-decayed velocity. The 2nd shot must not be swallowed, and 3rd+ shots must not hit instantly.