The Ultimate Firearms Guide

Chapter 1

Guns in Build 42

A gun is the strongest tool in the game. It is also the loudest. Learn both halves or it will get you killed.

This guide is about a video game. Real guns are never toys.

The deal you make with every shot

What changed from older versions

Old guides will steer you wrong. Build 42 rebuilt guns from the ground up.

The shooter's journey

1. BuildPick a job and traits that start you with Aiming.
2. FindGet a gun, the right ammo and magazines.
3. LearnMaster the keys before you need them.
4. AimStand still. Let the circle shrink.
5. PlanKnow where you run after the noise.
6. TrainLevel up on small groups.
7. CareFix jams. Repair worn guns.

Chapter 2

Build your shooter

Aiming is the slowest skill to train, because training costs bullets. Starting with a few levels saves hundreds of rounds.

The 2 gun skills

The 6 things Aiming improves

Higher Aiming also makes your guns jam less.

Best picks on the character screen

Read the books first

Books multiply your XP. Aiming and Reloading books are weaker than other skill books. They are still worth reading before you spend ammo.

Chapter 3

Know your guns

There are 20 guns. They fall into 4 families. Each family has a job.

All 20 guns

Damage is a range from weakest to strongest hit. Range and noise are in tiles.

Old name, new name

Many videos use the old names. This table helps you translate.

Chapter 4

Ammo and magazines

A gun with the wrong ammo is a heavy stick. Match them before you leave home.

Every bullet is treasure

You cannot craft bullets in the normal game. Every round you own was found as loot. When it is gone, it is gone. So never waste shots on a zombie you could hit with a bat.

Which ammo feeds which gun

Magazines: the part beginners forget

Some guns need a magazine. That is a metal box that holds the rounds. No magazine means no shooting, even with a full ammo box.

Chapter 5

Controls and handling

Fumbling keys gets survivors eaten. Practice these in a safe place first.

These are the default keys on a keyboard. You can change them in the options.

What "racking" means

Racking pulls the slide or pump. It moves a round into the firing chamber. If you reload calmly, your survivor racks for you. If you are rushed, the chamber may be empty. Then the gun only clicks. Press X and it is ready.

The reload wheel

Hold R with a gun in your hands. A wheel appears. From here you can load rounds into a spare magazine. You can also unload the gun.

Holsters

A pistol or revolver can ride in a holster. A holstered gun weighs less on you. It is also quick to draw. A double holster carries 2.

Single shots or full auto

The M16 has 2 fire modes. Single fires 1 round per click. Auto keeps firing while you hold the button. Auto burns a 30-round magazine in seconds. Use Single unless a horde is on top of you.

Shooting from a car

1. Press V to open the car wheel.
2. Open your window.
3. Aim and fire as normal.

Chapter 6

How aiming works

Build 42 shows you how good your shot is before you fire. Learn to read the circle and you stop wasting bullets.

The aiming circle

Hold the right mouse button with a gun. A circle appears at your cursor. It tells you 2 things:

• Size. A big circle is a sloppy shot. A small circle is a steady shot.
• Color. Over a target, it shifts from red (bad) through orange to green (good).

The circle shrinks while you stand still and keep aiming. So patience is free accuracy.

This toy shows the idea, not the game's exact numbers.

The 4-beat shot

1. StopPlant your feet. Moving ruins aim.
2. HeadPut the circle on the head.
3. WaitLet it shrink and turn green.
4. FireOne shot. Then check around you.

Why the head?

Bullets now hurt different body parts by different amounts. This matches how melee works.

The game helps a little. If your circle covers the head, it checks for a headshot first.

Use each gun's special trick

• Shotguns: aim at the middle of a tight group. One shell can hit up to 9 targets.
• Rifles: bullets pierce. Line zombies up in a row for a 2-for-1.
• Pistols: let them come close. Short range is where pistols shine.

Chapter 7

What ruins your aim

Your survivor is a person, not a robot. A scared, hurting, tired person shoots badly.

Level by level: Aiming

The best single thing to do at each level. Read the matching book first when one exists.

Your ticks are saved in this browser, on this device only.

Chapter 8

Noise: the dinner bell

Killing the zombie in front of you is easy. Surviving the 50 that heard it is the real test.

Every gun has a noise number. That is how many tiles away zombies can hear the shot. Sandbox: Firearm Noise Multiplier They all start walking toward it.

The 5 noise rules

1. Never shoot at home. You will pull the whole town to your front door.
2. Shoot, then move. Zombies walk to where the sound was. Do not be there.
3. Always have an exit. Park your car nearby, facing the way out.
4. Count your rounds. Leave while you still have ammo, not after.
5. Use noise on purpose. A shot can pull zombies away from a place you want to loot later.

Chapter 9

Weapon parts

Parts make a good gun better. They will not fix low skill, so train first.

The 11 parts

Chapter 10

Jams, wear and repair

Guns break down like everything else. Knowing the fix turns a panic into a 1-second pause.

Jams

You pull the trigger. You hear a click. Nothing fires. That is a jam.

Wear

Each shot has a small chance to wear the gun down. For a hunting rifle it is about 1 in 200. Higher Aiming and Maintenance make that chance smaller. A gun at zero condition is broken.

Repair

There is no gun repair kit. You fix a gun with another gun of the same family as spare parts. You also need some Aiming skill.

Right-click a worn gun to see what it accepts.

Chapter 11

Training plan: 0 to 10

Aiming XP only comes from hits. So the whole plan is about making hits easy and safe.

How the XP works

• You earn XP for each target a shot hits. Misses give nothing.
• Damage does not matter for XP. A weak hit counts the same as a strong one.
• You no longer get XP for every shotgun pellet. That old trick is gone.
• Below level 5, XP comes about 3 times faster than after it.

Chapter 12

Where to find guns

Guns are rarer in Build 42 than they used to be. Knowing where to look saves dangerous trips.

Homes sometimes hide a gun in a bedroom wardrobe. The chance is small, so do not count on it.

Chapter 13

Tips, tricks and fixes

20 tips from the firing line

Before the fight

1. Pick a job or trait with Aiming. It saves hundreds of bullets.
2. Read the matching book before you spend ammo.
3. Fill every magazine at home.
4. Carry a melee weapon. Guns are for problems melee cannot solve.
5. Keep a revolver as a backup. It never jams.

During the fight

6. Stop moving before you shoot.
7. Aim for the head. It does 3 times the damage.
8. Wait for a small green circle.
9. With low skill, let zombies come close.
10. Aim shotguns at the middle of a group.
11. Line zombies up for rifles. Bullets pierce.
12. Gun clicks? Press X.
13. Panicked? Back off and take Beta Blockers.
14. Use Single fire on the M16. Auto eats ammo.

After the fight

15. Move away at once. More zombies are coming.
16. Never lead the crowd back to your base.
17. Reload and refill magazines once you are safe.
18. Take scopes off before going indoors.
19. Keep broken guns as spare parts.
20. Store ammo in boxes. Open them only when loading.

Fix-it table

Chapter 15

Words and sources

Shooter's word list

Aiming circle (reticle)

The circle at your cursor while aiming. Small and green is good.

Round

One bullet, ready to fire.

Magazine

A metal box that holds rounds and slides into the gun.

Chamber

The spot inside the gun where a round sits just before firing.

Rack

Pulling the slide or pump to move a round into the chamber. It also clears jams.

Jam

A stuck round. The gun clicks but does not fire.

Bolt-action, pump-action, lever-action

Guns where you work a handle between shots. They fire slower but are simple.

Critical hit

A lucky, extra-strong hit that does at least 2 times the damage.

Pierce

When a bullet passes through one target and can hit another.

Noise radius

How many tiles away zombies can hear the shot.

Moodle

The small icons that show how your survivor feels, like Panic or Pain.

Desensitized

The Veteran's trait. It blocks almost all panic.

Sandbox

The settings screen where you change the game's rules.

How sure are we?

Every fact here was checked in September 2026 for game version 42.20.4. The order of trust was: official patch notes first, then the official wiki, then player data and reports.

The game still gets updates. A few things may differ in your game:

• The big gun table. Damage, range and noise come from a fan site that reads the game files for version 42.19. The MSR788 numbers matched a second source. Your tooltips are the final word.
• Which parts fit which guns. This changed during Build 42. Trust your Upgrade menu.
• Missing old parts. Older guides list an Iron Sight, Sling, Fiberglass Stock and Bayonet. Players report these are not in the current parts list.
• Zombies versus animals accuracy. This comes from one line on the official wiki for 42.20.4. It may change again.
• Job and trait numbers. These were last confirmed on versions 42.19 to 42.20.
• Default keys. They can differ if you changed your settings or use a controller.

Sources

• The Indie Stone, official patch notes for 42.8.0 (physics), 42.12.0 (body part damage for guns) and 42.13.0 (headshot priority)
• PZwiki (the official wiki): Aiming, Reloading, Firearm, Skill, Panic, Desensitized, Reluctant Fighter, M9 Pistol, M1911 Pistol, Patrol Revolver, MSR788 Rifle, MSR7T Tactical Rifle, Laser Sight, Red Dot Sight, x8 Scope, and the Aiming and Reloading skill books
• PZfans weapon data for version 42.19 (gun table, noise values, weapon parts)
• Steam Community guides and discussions on the Build 42 aiming circle