One of the iconic platforms chambered in the 5.7x28mm FN cartridge is the FN P90, and the company offers a non-NFA, semi-automatic variant for commercial sale in the US. However, this long-barreled model just doesn't look right, which makes this platform a candidate for an NFA-regulated SBR build. Enter CMMG and its PS90 barrel. The CMMG PS90 barrel is the correct length for a PS90 SBR, measuring in at 10.4 inches. The barrel is machined from 4140 chrome-moly steel and features a salt-bath nitride finish that protects it from wear and corrosion. The barrel features a 1:9-inch twist rate and is threaded at the muzzle with M12X1.0 LH threads. Now all that's needed to finish up your build is a PS90 flash hider or thread adapter!