[chaosagent]

Greenberg did not mention whether the homemade silencer was effective or not. It functionally changed the pistol from a semi-automatic to a manually operated repeater.

What is a 'manually operated repeater, and what does it have to do with a silencer?

[marktwain]

A “manually operated repeater” is a firearm which reloads with an manually powered action, such as a bolt action, pump action, or lever action.

The silencer/suppressor on the 3D printed reciever had to be manually cycled to reload the chamber with a new cartridge. It became, essentially, a straight pull action.

A semi-automatic chambers a new cartridge automatically.