After creating an auto cannon and mounting it, once I try to fire the empty cartridges go into my inventory but no bullet exits the cannon. I attempted to change the direction of the recoil spring, replace the cannon numerous times, and many other things to no avail.

Did you get autocannon cartridges from the search menu? Those cartridges are known to not function properly. If so, get your cartridges from the proper CBC tab

Awesome, thanks for the quick reply and helping me!