I recently installed Fallout 3 Weapons Restoration and found some of the weapons underwhelming. I made this for myself, but I uploaded it in case others wanted it as well.

This mod uses JSawyer's damage values for reference. I highly recommend installing JSawyer Ultimate Edition.

List of Changes:

.22 Revolver:
Damage: 13 > 18
Critical Damage: 26 > 36
Value: 110 > 150

Alien Disintegrator:
Clip Size: 100 > 200
Ammo Use: 1 > 2

Alloy Steel 10mm Pistol:
Health: 160 > 240
Value: 1000 > 2250

Alloy Steel Assault Rifle:
Damage: 19 > 21
Min Spread: 1.5 > 0.8
Clip Size: 30 > 36
Health: 350 > 750

Alloy Steel Combat Shotgun:
Damage: 63 > 90
Fire Rate: 3.43 > 1.5
Min Spread: 2 > 2.4
Max Spread: 4 > 4.8
Projectiles: 7 > 9
Health: 300 > 360
Value: 2200 > 6900
Strength Requirement: 5 > 6
Skill Requirement: Guns 50 > 75
Ammo Type: 20 Gauge > 12 Gauge

Assault Rifle:
Damage: 16 > 18
Min Spread: 1.5 > 1
Clip Size: 24 > 30
Health: 350 > 500

Captain's Sidearm:
Damage: 54 > 100
Critical Damage: 20 > 40
Fire Rate: 2.5 > 1.75
Ammo Use: 1 > 3
Value: 500 > 4000

Chinese Assault Rifle:
Damage: 18 > 21
Min Spread: 1.5 > 1.2

Chinese Pistol:
Damage: 14 > 22
Health: 150 > 200

Combat Shotgun:
Damage: 55 > 80
Fire Rate: 3.43 > 1.5
Min Spread: 2 > 3
Max Spread 4 > 6
Projectiles: 7 > 9
Health: 300 > 240
Value: 2200 > 4600
Strength Requirement: 5 > 6
Skill Requirement: Guns 50 > 75
Ammo Type: 20 Gauge > 12 Gauge

Deathclaw Gauntlet:
Damage: 35 > 40
Critical Damage: 52 > 60
Health: 600 > 75
Weight: 5 > 10
Value: 150 > 500

Double-Barrel Shotgun:
Damage: 112 > 135
Min/Max Range: 500/2000 > 192/750
Health: 250 > 100
Value: 1750 > 3000
Skill Requirement: Guns 25 > 50

Dragoon Assault Rifle:
Damage: 21 > 24
Min Spread: 1.5 > 1
Clip Size: 36 > 30
Health: 400 > 600
Value: 5500 > 3300

Dragoon Pistol:
Damage: 18 > 28
Health: 150 > 300
Value: 300 > 1500

Infiltrator:
Health: 350 > 500

Lever-Action Rifle:
Critical Chance: 1% > 3%
Spread: 0.25 > 0.06

Railway Rifle:
Min Spread: 0.75 > 0.025
Spread: 1.5 > 0

Replica Repeater:
Critical Chance: 2% > 3%
Min Spread: 0 > 0.05
Spread: 3 > 0

-Added Firelance, the unique Alien Blaster from Fallout 3. You can find it inside the Remnants Bunker.

Firelance:
Damage: 60
Critical Damage: 40
Critical Chance: 100%
Clip Size: 20
Ammo Use: 2
Ammo Type: Alien Power Modules
Special Effect: 2 fire damage for 5 seconds.

Alien Power Module recipe:
-Requires 2 Energy Cells for 1 Alien Power Module. Vigilant Recycler and 90 Science are required. The catch is that every Alien weapon now uses a different amount of ammo.
-The Alien Atomizer uses 1 Alien Power Module, the Alien Disintergrator uses 2, and the Captain's Sidearm uses 3.

Reasons for every change:

.22 Revolver: JSawyer buffs the Silenced 22 Pistol from 9 > 12 damage. It holds 11 more rounds and is silenced. This adds a .22LR weapon that deals decent damage. It works well with Hollow Point rounds on low DT targets.

Alien Weapon Changes:
I thought it was cool that the original mod added in the Alien Power Modules from Mothership Zeta. I always wanted to make a mod for renewable Alien ammo and the Alien Power Modules are perfect for it. It would be pretty lame if you had 4 weapons that you don't have ammo for. So now only the Alien Blaster can run out of ammo.
-The Captain's Sidearm was changed to be an Alien Blaster replacement when you run out of Alien Power Cells. It's about as strong as the original Alien Blaster.
Alien Blaster: 75 Damage + 50 Critical Hit Damage x 1.75 = 219 DPS
Captain's Sidearm: 100 Damage [+40 Critical Hit Damage(Only a 1% chance like in Fallout 3, but you can sneak attack crit)] x 1.75 = 175 DPS [or 245 DPS with a crit build].

Alloy Steel + Dragoon Weapons: Now they all have 50% more durability and value than their standard counterparts with some exceptions. They also retain their clip size changes with some tweaks. The Alloy Steel Assault Rifle and the Dragoon Rifle had their clip sizes swapped to be inline with the new assault rifle changes. The Alloy Steel 10mm Pistol has 300% more durability and value than it's standard counterpart. This gives it a reason to exist alongside a fully modified standard 10mm Pistol and the Weathered 10mm Pistol. The value increase makes it close to the value of other Alloy Steel weapons. In the original mod, all Alloy Steel and Dragoon weapons had a weapon description of "Increased Durability". This wasn't actually applied to the weapons however.

Assault Rifle Changes: In Fallout 3 the Chinese Assault Rifle is a complete replacement for the Assault Rifle. I took some creative liberties to make both of them have their own uses. The Chinese Assault Rifle deals a lot more damage than the Assault Rifle, but the Assault Rifle holds more ammo, has less spread and more item HP.

Chinese Pistol: The default damage of 14 makes it just as underwhelming as it's Fallout 3 counterpart. It now has 22 damage, same as the 10mm Pistol. With JSawyer and Grunt, the 9mm Pistol is capable of 22 damage as well. The Chinese Pistol also doesn't get any weapon mods. The Chinese Pistol can now make a great early game sidearm.

Combat Shotgun: It fires as fast as the Fallout 3 Combat Shotgun now instead of like a machine gun. It does more damage than the Hunting Shotgun and has a bigger clip size, but it suffers from significantly more spread and 9 projectiles(Equal to Fallout 3).