Perhaps newer garage guns? To explain;
a "garage gun" is a home made weapon, typically of the fully automatic variety, and normally based off of a pre existing template.
The reason I suggest such an outlandish form of weaponry is because in a "the world has ended" scenario people will inevitably begin to produce their own armaments. Having said the the quality of such arms does not actually need to be substandard or poor. Take a look at the gun runners, they managed quite well to re-arm the west.
So in this concept you could easily have a few high end guns/weapons floating around the waste that are actually fairly new. However there is the down side as there will most indeed be a great many worthless zip guns as well.
I often find adding a little bit of chaos to games to be worth while particularly if your DM makes players roll for loot based on various factors.
Image if you are using the basic special system and luck is a factor for all loot rolls, but even then the over all pay out is always at the option of the DM.
This could also aid in adding different layers of the game as players could receive various different qualities of the same gun template.
For example: a Standard 9mm Pistol
In this scenario the gun could potentially have different characteristics depending on the quality.
Zip gun version would be of course the lowest quality
Pre-war version would be considered the standard pattern
Rebuilt version would be a better version of the pre war version
Manufactured New version could be the best
In this scenario the requirements for use of the gun could be increased or reduced depending on the quality of the gun, like action points, weight, etc..
Other variables may also play a roll as a better crafted weapon could be more accurate, have more range, or suffer less stopages or "jinxed" moments.
Food for thought, have fun.
