Sak Lunch / Lunchbox Barrels

Description

The Sak Lunch 6″ (Sig Cross) barrel & Lunchbox 5.2″ (Q Fix) barrel are available for order.

Barrel Specs;

Our barrel is a high-end premium 416R stress-relieved button-rifled 1:3t or 1:5t blank that’s CNC machined on a Mori Seiki lathe, chamber is precision dialed in and chambered concentric to bore guaranteeing the lowest runout, and finally threaded M18x1.5  with a Q taper, precision square-cut crowned, and finally black Nitrided (1:3t Only)

Nitrided barrels are treated through a thermochemical process that diffuses nitrogen and carbon into the steel’s surface.

The primary benefits of nitrided barrels include:

• • Superior Accuracy: Unlike chrome lining, nitriding is a surface treatment rather than an additive coating. It does not change the barrel’s dimensions, preserving the precise rifling and bore geometry as they were machined.

  • Extreme Surface Hardness: The process creates a hard “skin” (often up to 60-70 HRC) that is as tough as tool steel. This significantly reduces throat erosion and wear on the rifling lands.

  • Comprehensive Corrosion Resistance: Because the barrel is submerged in a chemical bath, both the interior bore and the exterior surfaces are protected. This treatment is extremely resistant to rust and often requires less oil for maintenance.

  • Increased Lubricity: The treatment lowers the coefficient of friction within the bore. This leads to less copper and carbon fouling, making the barrel significantly easier to clean—often requiring only a simple wipe-down.

  • Heat Resistance: nitriding offers excellent heat resistance for semi-automatic and rapid-fire strings, maintaining accuracy longer than untreated steel.

  • Fatigue Strength: The process can improve the fatigue life of the steel by 30% to 100%, making the barrel more resistant to structural failure under stress.