Description
A commercial-production clone of the 10.3″ barrels built for the US Army — made to the same drawing by the manufacturer that fulfilled the contract. Material, rifling form, chamber dimensions, chrome, finish and markings all follow the government print rather than a commercial interpretation of it. This was the first government-procured barrel specified with a low-profile gas block instead of a front sight base, and the FSB journal is still present if you want to run one.
CRANE-spec .0705 gas port, sized to the specification and configured to function with full-power 5.56×45 NATO ammunition on a standard carbine-weight buffer — no special buffer system required. Two gas block set-screw dimples at .425 spacing per the official drawing, grenade launcher flats, and the full marking set: caliber, twist, CAGE code, production date, magnetic particle inspection and chrome-line facility.
The low-profile gas block is installed and pinned before shipment — port alignment verified, set screws torqued to specification, and a stainless steel coiled pin through block and barrel. Dimples locate it, screws clamp it, the pin stops rotation. This barrel configuration is designed to pair with the LMT® 9.25″ MRP™ upper receiver; other rail lengths will run, and we confirm clearance before shipping.
Converted to the LMT® MRP™ barrel interface, then inspected, gauged and assembled by the Second of Ten build team to a documented standard. Installs with the MRP™ upper’s factory barrel hardware — no proprietary tooling and no permanent modification to the receiver. Headspace is gauged and recorded on the barrel inspection record before shipment.
Ships shooter ready: gas tube installed and the muzzle protected by the SOT Standard Barrel Thread Protector (CNC-machined steel, black or nitride finish), with no muzzle device fitted. Brakes, flash hiders and suppressor mounts are fitted and timed to order through the SOT Custom Shop. A headspaced bolt carrier group can be added and gauged to this barrel: SOT Enhanced HM Defense in Black Nitride, or the SOT Enhanced Microbest Super-Stake with the Young Manufacturing HMB™ bolt.
Includes
- 10.3″ Government-contract clone barrel, converted to the LMT® MRP™ interface
- Low-profile gas block, installed, aligned, torqued and pinned
- Gas tube sized to the gas system, black nitride finish, installed
- SOT Standard Barrel Thread Protector, fitted (CNC-machined steel, black or nitride finish)
- Vacuum-sealed, with a Zerust® corrosion-inhibitor tube in the bore (remove before firing)
- Barrel inspection record (SOT-BIR-001)
Options
- Headspaced bolt group: SOT Enhanced HM Defense, Black Nitride
- Headspaced bolt group: SOT Enhanced Microbest Super-Stake with Young Manufacturing HMB™
- Muzzle devices from other manufacturers, installed and timed — for a specific muzzle device, please ask before ordering
Matching headspaced bolt
Choose a bolt above and we gauge headspace with it in this barrel and record the pairing on the barrel inspection record, so the two ship as a matched set.
Full specifications, photos and the inspection standard
Shipping: we do not ship barrel assemblies to CA, CT, DE, DC, HI, IL, MD, MA, NJ, NY, RI or WA, or to Denver, CO or Cook County/Chicago, IL. Questions? Ask your local FFL.
WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
