So, Modern20 Revised (working title), is turning into a major expansion.
In addition to numerous small bug fixes, including a tweak of firearms damage to bring the numbers a little closer to reality, Modern20 Revised will bring the following to your game:
33 new feats
140 small arms from Prohobition, WWII, Cold War and Modern eras (Modern20 original had 39 firearms). Not all the new firearms are older weapons either, many of the new firearms are modern.
New rules for scopes and small arms targeting systems.
Material from Modern20 Supplement #1, including 4 new occupations, 2 new skills, and a host of new options for Hit Location, now core.