Fallout 4 weapons

Unlike previous installments, in Fallout 4, weapons fall under three classifications: Normal, Legendary, and Unique. Normal weapons have no special statistics on them whatsoever. Legendary weapons come with random bonuses applied to them, and are only dropped by Legendary Enemies. Unique weapons are weapons that are already named and will always retain the same special bonus. Uniques are typically either bought off of merchants or quest rewards. Normal and Legendary weapons will change their name when mods are applied. Unique weapons will not.

All stats are given with standard weapon modifications. Values in parentheses are the maximum (minimum for weight and AP cost) values in class (some weapons, like the pipe pistol, become short rifles when changed from a grip to a stock weapon). Note that not all maximum values will come from the same gun - for example, maximum damage and maximum rate of fire will typically require mutually exclusive mods.

Other
All these weapons count as non automatic weapons and thus work with either Gunslinger, Rifleman or Sniper respectively, except the Cryolator which is counted as a heavy gun and thus works with Heavy Gunner.

Explosives
Explosives have a maximum range of 93. They seem to hit an invisible wall at their maximum range. Explosives benefit from the Demolition Expert perk.

Bladed
Bladed weapons can dismember limbs of humanoid opponents, permanently damaging the limb and disarming the target. Like all melee weapons, bladed weapons benefit from Big Leagues and Strength.

Blunt
Blunt weapons tend to stagger opponents more frequently than bladed weapons. Like all melee weapons, blunt weapons benefit from Big Leagues and Strength.

Fist weapons
Fist weapons benefit from the Iron Fist Perk as well as from Strength.

Renaming weapons
In Fallout 4, the player character is able to rename any weapon, including unique weapons, at any weapons workbench. Renaming weapons does not affect any weapon stats. This primarily adds a level of personalizing to weapons and can help avoid accidentally disassembling a favored weapon, but it is also possible to use certain HTML element tags for added customization. Some HTML tags that can be used are listed:
 *  italics
 * underline
 *  list (bullet-point)

To keep your crafted weapons at the top of your Pip-Boy weapon list, put a hyphen (-) or a blank space at the beginning of the name, or if using one of the above HTML tags, simply capitalize the letters inside them (i.e. a weapon named " Blade " will be sorted above a weapon named " Blade ").

Note that these tags are only visible within crafting menus; the 'formatted' text will appear in the Pip-Boy.

Mods
In Fallout 4, modification of weapons are in fact just applying mods to them. Every weapon have mods slots, like barrel, grip.... and each slot can get some mods. The fun (and obsure) part is, you don't need the perks to apply modification, you just need it to create the mod from scratch. When you find a weapon with a mod you can't create, just craft anything in place of this mod and it will go into your inventory. You can then apply it on any weapon of the same type. The real limitation is with Unique weapons, as the mods are "reserved" for this kind of weapon and can't be used on another weapon, and of course as the weapon is unique you can't find another one with better mod, so the only way to improve Unique weapons is craft mods yourself.