Primary Weapons MK109 Mod 1-M Upper Receiver 9.75 Barrel 300BLK

Primary Weapon Systems

Overview

The Primary Weapons Mk109 Mod 1-M Upper Receiver features a complete assembly with a 9.75-inch barrel designed specifically for the 300 Blackout caliber, making it suitable for a range of shooting applications from suppressed subsonic rounds to full-power ammunition. With a twist rate of 1:8, this upper receiver allows for optimal stability and accuracy with a variety of bullet weights, which is crucial for builders looking to fine-tune their performance. This upper is commonly found in builds focused on the 300 Blackout caliber, appealing to those who prioritize versatility and compactness in their AR-15 platform.