Shaw PS90 10.4" Threaded SBR Barrel

The Shaw PS90 10.4-inch barrel is the standard path to a registered short-barrel PS90. ER Shaw cuts the barrel from 4140 chrome-moly steel, melonite-finishes the bore and exterior, and threads the muzzle 1/2x28 so any standard 5.7x28 suppressor mounts direct-thread without an adapter or shroud.

Installation requires an approved ATF Form 1 SBR registration before the user can legally swap to the 10.4-inch barrel. Under OBBBA the SBR making tax is zero, and 2026 Form 1 eForm approvals run in days, not months. The barrel itself is a drop-in replacement for the factory PS90 barrel and shroud assembly; the user removes the factory barrel from the PS90 receiver and installs the Shaw barrel using the existing PS90 barrel nut and tooling.

Compared to the CMMG SBR conversion, the Shaw barrel is the cleaner pick: native 1/2x28 threads (no CMMG M12x1.0 LH adapter required) and a more accessible price point. The 1:9 twist is appropriate for the SS197SR and SS198LF 5.7x28 loadings.