I decided to make a spreadsheet. Note that I don't think most weapons can be upgraded to do +1 dmg. Credits to Jeni for all the gun stats and information.
Another really important thing to note is there is a hit timer I believe. Meaning some bullets might pass through without hitting. I have no way of knowing how to calculate that in. Read the first page for other important notices about the document.
These are not guns in auctions. They are from the page 1 and 2 of shops in era guide.
https://docs.google.com/spreadsheet/...Wc&output=html
In the future I want to add photos :P
If anyone wants access and modify the document on google.docs let me know, it would let you make changes. It updates itself live and even features a chat box between all the people in the document. Curious if anyone might want to update it. Because it would be nice to keep it updated with recent information.