This could aptly be described as the 'Gun Bunny' issue of Wisdom from the Wastelands - it's jam-packed with information (both flavour text and good solid game mechanics) for a whole bunch of ammunition types for both firearms and bows, as well as additional rules for range and a few accessories.
For the budding gunsmith, there are numerous modifications that can be made to your weapons. Remember that in the 'post-apocalyptic' genre, the corner gunstore may well not exist any more and if you want to repair or improve your weapons, it will be up to you! Likewise ammunion doesn't always come in bright boxes, you will end up having to hand-load. To make a modification you need to be proficient with the weapon in question, you should have the necessary parts to hand, and you have to make a successful repair roll.
For those who upgrade their sights, there's a neat table which enables modifications to targetting rolls depending on what sights you have - so the effort is made worthwhile.
A little more on handloading, beyond a simple list of ammunition types and their game effects, would have been nice, but otherwise a very useful resource for those who want to take the art of gun and bow combat to greater heights than mere survival.