These superlative match-grade barrels are designed for precision fitting by a skilled gunsmith, ensuring the tightest lockup and superior accuracy by tailoring them to a specific slide/receiver pair. Unlike "drop-in" barrels, they require meticulous fitting, including reaming to achieve the correct headspace and adjusting the hood, lugs and feet. However, the innovative geometry of Nowlin's pre-cut top lugs typically necessitates only minimal fitting to attain optimal lug engagement. Crafted with State-of-the-art electro-discharge cathode machining (ECM), these barrels boast groove and bore tolerances held to an astonishing .0002 inches. The rifling is exceptionally smooth, uniform and precise, enhancing velocity and performance. The smooth-cut rifling design not only boosts velocity but also features a unique angled edge on the driving band, providing a superior gas seal. This results in reduced fouling with all bullet types and extends the barrel's lifespan. Strategically adding extra weight at the muzzle, these barrels help control recoil, enabling faster follow-up shots by keeping the front sight down and on target. Additionally, they replace the bushing and increase the lockup area, further enhancing accuracy. These barrels are the epitome of precision engineering, offering unparalleled performance for the discerning shooter. The Nowlin government model 5 inches bull barrels necessitate gunsmith fitting to achieve precise lockup and optimal accuracy This process includes short chamber reaming and the fitting of the hood, lugs and feet The barrels are manufactured with exceptionally precise groove and bore tolerances of 0.0002 inches, achieved through electro-discharge cathode machining This process results in ultra-smooth, uniform rifling, which enhances velocity and improves the gas seal These barrels are engineered to add additional weight at the muzzle, effectively controlling recoil and facilitating quicker follow-up shots They replace the bushing and expand the lockup area, thereby enhancing accuracy