The skill of gunsmithing is the art to craft weapons, to repair or to modify them. The crafted weapons are used with the appropriate weapons skill. On the following sites one finds, among other things, examples for self built weapons, a rough idea on how good the gunsmith must be to create
them and what kind of materials they would need.

Projectile weapons:

Projectile weapons are, as the name says, devices that propel projectiles to high speeds. Fundamentally, an experienced gunsmith can without any problem, repair a pre War weapon, as long as he has the fitting replacement part – or, depending on the options that his workshop gives him, is able to fabricate that replacement part.

The following paragraphs lists some simple and not so simple self buildable projectile weapons.

Pipe gun: Basically just a pipe in the diameter of the cartridge caliber. One loads the cartridge into the back, then maybe locks up the shoulder stock and a simple trigger makes sure, that something hits the primer.
One needs a pipe, therefore, something that can act as a hammer or striker, a kind of trigger and enough screws and metal parts to connect all of that together. Bonuses can be given for using a firing pin or a shoulder stock. Is the pipe smooth and not used for shot, the accuracy will suffer that lack of rifeling,

Ammunition:

Damage:

Minimal strength:

various

Depending on the caliber

3 for pistol ammunition

5 for rifle ammunition

Dart pistol: A pistol that shoots small, plastics or metal darts. Since it operates with pressurized air or something similar, it’s extremely silent.
The crafting is more complicated than the pipe gun. One needs a pistol grip, a trigger group, a fitting canister of pressurized air and of course the ammunition, as well as possibly an automated or semi automatic ammunition feeding mechanism and at least duct tape to connect all of that … but proper glue and real tools would be a lot better.
Bonuses can be given, for example, for using high quality materials or real darts as ammunition instead of simple metal balls.

Nail gun: Similar to the dart pistol – only fresh out of an ever sicker mind. This weapon fires large nails, like those used for train tracks, for example. One needs a strong energy source, like a car battery or a micro fusion battery, as well as a barrel and a trigger group and something to propel the
nails – be it pressurized air or electromagnetic rails. Depending on the weight of the weapon, it might be one that only a supermutant can hold.

Ammunition:

Damage:

Minimal strength:

Nails of various sorts

2 D6

4 -7

Slingshot: A spanable sling, that shoots clunky projectiles like stones (or even hand grenades) far. Everything one needs is a kind of grip (pistol grip, shoulder stock, whatever, and good, stable rubber for the sling). Especially good versions have folding sights like those found on grenade launchers or mechanical help to span, like a tooth gear, which lowers cadence but raises the range.

Close combat weapons:

On the following pages are a few suggestions for self built, better close combat weapons. As with the projectile weapons before, these are just a few limited suggestions. If you have a good idea for a melee or unarmed weapon, that can not be found in the rules but would be easy to build in the post apocalyptic Wasteland, create it yourself.

Shot-Glove: The Shot-Glove is a glove with a small firing pin attached behind a 12 gauge shot shell. The firing pin hits the primer when one hits someone with the fist. The result is a horrible, often very well aimed shotgun wound. The fact that it lacks a proper barrel is inconsequential in this
design, since the shot does not have to travel any range.

Schishkebap: The Shishkebap is, to make it short: a flaming sword. What’s needed is a blade, a tank for the napalm (or whatever other flammable liquid one uses), a hose and of course a grip with a built in method of not only soaking the blade with napalm (or whatever) but igniting it, too.

Bombs, traps and mines:

Improvised claymore directional mine: Claymores (also called directional mines) are rather simple constructions with a gigantic potential for destruction. They are composed of a piece of explosives with a detonator on one end and a load of shrapnel on the other side. They are obviously easily self built. All one needs is explosives, a load of shrapnel and a detonator.

One can of course secure a room with a claymore, by using the skill hunting traps in conjunction with a tripwire and the claymore.

Pipe bomb: Pipe bombs are simple, self built hand grenades. They are made of primitive explosives in a pipe, often just simple black powder, often with a load of shrapnel and – of course – a simple detonator. The black or smoke-free powder can be taken from ammo. If you dismember a cartridge,  it would be advisable to also take the primer as a detonator.

Molotov Cocktail: The probably most simple to craft weapon there is. One only needs a bottle, a rag and a flammable liquid.