RimWorld Weapon Balance is a series of mod patches that are intended to bring balance to various mods.

The mods are balanced according to the averages between them, not vanilla. This means these balance patches are slightly stronger than vanilla, but not by an excessive amount.

Individual weapons are given a CR, or "Combat rating" Which is calculated from the weapons range, damage, and accuracy stats. As well as other factors such as movement penalties or special abilities.

Once every weapon has a CR assigned to it, they are split into categories based on type, there's Assault rifles, Semi-Auto rifles, Handguns, Machine guns, Shotguns, Sub-machine guns, Sniper rifles, Heavy weapons, Launchers, Grenades, Primitive, Specialized, and Melee.

The average CR for each category is then worked out, and used as the base line in which all weapons will be balanced.
This baseline is then broken up into 4 tiers. Weapons are assigned a tier based on multiple factors, such as difficulty to obtain, tech level of the weapon, and required research to craft them.

Industrial Combat Rating, or ICR -These are weapons like the vanilla assault rifle, and only require machning to make, or equivilent research. Any weapon that can also be obtained before machining, and isn't primitive or a melee weapon ends up here.
Waepons in this tier are -30% to -15% wearker than the average CR.

Industrial Combat Rating+ Or ICR+ - This group of weapons are industrial tech weapons that require additional research on top of machining, or weapons that require rare materials or components, Or weapons that are harder to obtain than normal.
Weapons in this tier are -15% to 0% weaker than the average CR.

Charged Combat Rating, or CCR - These are early tier Spacer weapons, and cover weapons like the vanilla charge rifle, or any weapon that unlocks with the charged rifle research. Exceptionally rare industrial weapons can end up in this category as well.
Weapons in this tier are 0 to 15% stronger than the average CR.

Charged Combat Rating+, or CCR+ - These are weapons that require research beyond charged shot, or are exceptionally powerful or difficult to obtain. Weapons like the minigun are in here, and mods like Glitter Tech and Orassans are in this tier.
Weapons in this tier are 15%-30% stronger than the average CR.

Charged Combat Rating++, or CCR++ - Weapons in this category fall into one of two areas. Weapons that require charged shot research, and an excessive amount of research past it, usually 2 extra research topics past charged shot, as well as additional components to craft that cannot be easily acquired. Such as rare drops only. Weapons that require rare materials but don't require excessive research fall into the CCR+ category.
The other area are weapons that are intentionally rare, and powerful, weapons that are supposed to be "rare" or "unique". Weapons like this are placed into this category so they can serve their purpose as being special, with out being excessively overpowered (which they often are in mods.)
This tier if only 30-40% stronger than the average, and experiences a much smaller range than tiers below it, this is to help maintain some sense of sanity to the power scaling of items in the world, as by this point you're looking at some exceptionally powerful items when comapred to the average assault rifle. The point of this tier is to reward going above and beyond what's honestly needed to do well, and acquiring those difficult to obtain resources, or spending the extra time researching even more powerful weapons, when you're already got access to the cheap and cost effective weapons of charged shot. Weapons in this category probably aren't worth the trouble, but are indeed more powerful than anything else you'll ever find.

Here's the documentation of my work. Which is going to forever be a work in progress. Feedback is welcome, if you spot an error or flaw, or have suggestions to improvemy CR calculations, please share.
And mod makers! If you want to make your own patch, please contact me so I can help you out.

Documentation
https://docs.google.com/spreadsheets/d/18sS12brn0e_xDUs4KxYvBX1kTHmOjzvqchZyHNREWMc/edit?usp=sharing