It’s been said before that the heart of a rifle is its barrel. We’ve covered Rosco Manufacturing several times before, having witnessed firsthand their fully in-house approach to producing high-performing AR barrels at affordable prices. In 2021, they launched the first product in a new line of barrels they refer to as their K9 line.
The idea behind this line is to manufacture what Rosco calls a Performance Duty Barrel that blends the best features of traditional match-grade barrels with hard-use barrels intended for duty and defensive use. The K9 line starts with 416R stainless steel bar stock with a continuous taper profile, recessed target crown, finished in black nitride, and with a goldilocks gas port optimized to run reliably in both suppressed and unsuppressed setups. All K9 rifles are chambered in 5.56mm NATO with a 1:7 twist rate, again with an eye toward duty use and military-spec ammunition.
12.5
The first K9 barrel featured a 12.5-inch barrel with a new gas system length they’ve dubbed “patrol length,” which sits right between carbine and mid-length. The patrol length system increases reliability in shorter barrels when compared to a true mid-length, without the over-gassing and harsher recoil sometimes encountered when
