For a secondary weapon addition, first tests of a hand held rocket gun are successful. Somewhat similar in concept to the rocket gun out of the 60's once used as a prop in a James Bond movie.
Fires a small rocket propelled explosive projectile instead of a bullet. Slow rof. ATM 1 round per second for testing. Ammo and magazine counts will probably be similar to the magnum. Being a small projectile, explosive radius and force is small. It also trades explosive force and less impact damage. The impact will hurt but its not a tube insta-kill. As a projectile, there is an 'activation' distance. If too close, there will be impact damage but no explosion. It will be fast but still has a travel time and not the instant hit of a bullet weapon. It will destabilize after a distance. There is a short-lived projectile trail. So when you fire it, enemies close by will see the direction it came from if they are paying attention.
Going to take some careful balancing to make sure its not too good nor too weak. Its a sidearm not an rpg. For one, its not very useful at very close range since it wont activate in time, impact damage is small and rof is slow. So probably not the best weapon if you primarily go room to room. Some people lead first with a tube to get the impact kill but that wont work here. And no, there will not be a full-auto rocket gun.
Will upload a test vid tomorrow. Still working out some quirks. But feel free to leave opinions.