OfficerNoodle's Guide to the new Gun Factory System
Go to the Realtor Office ( one inside Town Hall and one near the Super Market ). Once you are inside speak with the Real Estate NPC and either purchase the deed or rent out one of the three warehouses.
Go to the Hardware store and speak with the Appliance NPC. Purchase a Conveyor Belt, Storage Box, Ore Crusher, Furnace.
Go to the building that you bought. Deploy your Ore Crusher and connect it to the power source with your hands. Pressing e on the outlet will pull the plug out.
Deploy the rest of your factory equipment such as Furnace, Storage box, and Conveyor Belt. Once they are deployed snap them together. Press E on the Conveyor Belt to turn it on/off after you have placed it
Now that all of your equipment is placed down and ready to go we can begin the fun part. Walk over to your Ore Crusher and hold e to turn it on. Make sure that the ore you placed is touching or almost touching the air vent. Or just stack a bunch in the front and it will crush them over time. After the ore in the crusher has been broken down put it in the Furnace to be smelted into bars.
Hold E on the Storage Box to view what you have crafted from the Factory so far. Then put those items back into the Furnace if they are bars or weapon parts. The picture listed below and above are the most repetitive and time consuming parts of the Factory System.
Enjoy your newly crafted weapon
I included a video that shows me going through the whole process of making a Mac 11.