The Horse's Name is Friday was intended to be a horror game. So my approach to designing new weapons should be that each has some key disadvantage the player would have to work around. The desired effect being that the player would always be on the back foot. 

My solution was mainly to change how each weapon behaved. The basic starting pistol was made to be single action, which in gameplay terms meant that the player had to manually pull the hammer back by pressing the fire button before firing again. This drastically reduced the pistol's rate of fire, and its ability to handle multiple or more powerful groups of enemies. 

The repeater was the first new weapon I designed, and was the first to fall into the 2 handed category. This meant that the player had to ready it before they could fire, pressing the fire button to bring it up to their shoulder.  The coach gun was the second two handed weapon added. While the coach gun was very powerful, its ammo was very rare and it could only hold 2 shots before needing to reload.

Ultimately combat in The Horse's Name is Friday did not reach the exact feel that I was going for. However, I would argue this was due to the lack of time and resources inherent in the fact that it was a roughly 10 week long project. With more tuning and time, I believe the systems implemented would be able to produce the desired experience.