The Thunder Ranch product line is a joint venture between Aero Precision and Thunder Ranch. Aimed to achieve Clint Smith's ideal purpose built "Ultimate Carbine", these products include key features requested from Clint Smith himself but with an Aero Precision flare. Like everything surrounding the Thunder Ranch name, you get exactly what you need - nothing more and nothing less.

The M4E1 Threaded Upper Receiver features an angular machined design that helps it stand apart from standard mil-spec upper receivers. This upper receiver features the same enhanced body profile as our M4E1 Enhanced Upper Receiver but is threaded to accept a standard AR15 barrel nut. It is forged from 7075-T6 Aluminum, precision machined to work with all mil-spec AR15 parts and includes the port door pre-installed.