Full changelog

The most verbose description of the gauss ammo comes from the fallout tabletop rulebook which released this year, you can find it's excerpt at the bottom of this page:
https://fallout.fandom.com/wiki/2mm_electromagnetic_cartridge_(Fallout_76)
It sounds like it's basically a battery pack surrounding a metal slug. As such, in CFWR, I elected to make it a hybrid guns/energy weapons ammo, requiring electron charge packs, microfusion cells, and some lead to craft.
As such, I removed the 556 casing models from all the weapons, and the crafting and breakdown recipes. The new recipes are carbon copies of the 2mm EC from CFWR, which I balanced against my S6S Ammo Rebalance file, which created a smooth, intuitive ammo crafting balance, which got more difficult to craft as ammo increases in power. I also included the feature I thought of in that mod, wherein 2mm, by virtue of it's combination of the charges in the ECP and MFC, can be used to charge new alien power cells at very high level skills.
In the CFWR patch, I intend to reconfigure the ammo from your side into a new one. I originally suggested to Webb to have a lightweight 2mm variant, that did less damage, but less weapon condition damage, but he wasn't into it. The ammo in yours could be reconfigured as such, but I actually really like the EMP version of the gauss pistol here, so I actually think that they should be special EMP rounds of some variety instead, for the static version to use specifically. The PPK12 could also optionally be allowed to use it as well.

To differentiate between CFWR's 2mm and yours, I added a f76 tag to the end of each of your 2mm items.
Casings don't have value or weight in NV, so they were removed.

Weapon mods were renamed for consistency
The accelerator barrel and grenade mags were remade into an item mods, because they can still be used at the workbench as normal, and so that they get caught correctly by item tag mods
There was a gauss accelerator in the grenade pistol cond lists
There was definitely no reason to add the vendor 2mm ammo lvli to the gauss pistol condition list in the script, that would cause ammo to spawn with ammo sometimes, instead of a gun
Coming with 42 2mm ammo by default then up to 5 chanced didn't really make any sense, max changed to about 5-7 depending on the weapon
Your accelerator recipe name didn't match the gun's actual name
2mm breakdown was granting a non playable robot 556 ammo
The recycling recipe also was a breakdown recipe
All crafting recipes are invisible if you don't have their components
The new crafting categories have been removed
Vendor max ammo count has been reduced substantially
Non emp pistol resist types changed to none since they're just a ballistic projectile
Silencer effect values should be 1, fixed
A bunch of the mod effects were non int values or kinda wildly large, they've been reduced and fixed
All the weapons had lots of values reworked for tier 4
Vats hit chance was upped to a base of 45%
Added moderate energy weapons skill checks to the barrel conversion recipes

Added a config ini that can disable each pistol type's wasteland integration, the note and chest, and optionally convert the weapons to a user configurable big guns skill level


Things I still didn't fix because they depend on your decision:
What's up with the weapons having both a scope and an iron sights mod at the same time? Seems like the IS is used for a lil spread adjustment, but I'd personally rename it custom parts or something instead.