I would love to see more sidearms. The regular Caldwell Conversion is very meh.
How about a Revolver with Speedloader but low Capacity like 5 shots.
Furthermore a reload speed perk could be cool. It should increase the reload speed on some slow reloading weapons (where no strips or speedloaders are used or adds them as a perk). It should be a low cost perk (3 maximally 4 points).