The Hornady .303 Caliber .312" 150 Grain Spire Point InterLock® Bullets (model 3120) are component projectiles engineered specifically for handloaders loading .303 British and other firearms with true .311" to .312" bore dimensions. Featuring Hornady's InterLock mechanical design, the jacket incorporates an interior ring that embeds into the lead core during impact, preventing jacket-core separation and maximizing weight retention. Paired with an exposed soft lead tip and a secant ogive profile, these flat-base hunting projectiles offer consistent barrel alignment, predictable expansion, and deep penetration on medium to large Australian game.

• InterLock® Retention Ring: A raised mechanical ring inside the jacket locks directly into the bullet's one-piece lead core to maintain mass and maximize penetration during terminal expansion.
• Secant Ogive Aerodynamics: Combines a streamlined ogive profile with an extended bearing surface, producing a 0.361 G1 ballistic coefficient for flat trajectories and stable in-flight ballistics.
• Controlled Expansion: Features an exposed lead spire point, internal jacket flutes, and a tapered jacket wall designed to initiate and regulate mushrooming down to moderate impact velocities.
• Cannelured Flat Base: Includes an engineered cannelure that allows secure crimping for consistent seating depth in magazine-fed rifles, including Lee-Enfield actions.

Key Specifications

• Calibre: .303 Calibre
• Bullet Diameter: 0.312 in (7.92 mm)
• Bullet Weight: 150 grains (approx. 9.72 g)
• Bullet Profile: Spire Point (SP) Flat Base with Cannelure
• Ballistic Coefficient: 0.361 (G1)
• Sectional Density: 0.220
• Package Quantity: 100 unprimed component bullets per box
• Cartridge Compatibility: .303 British, as well as .311–.312" bore rifles including 7.62x39mm and 7.62x54mmR supported by 150-grain load data

Who is the Hornady .312 303 Cal 150 Grain Sp Interlock Bullets 100 Pack – For 303 British for?

• Lee-Enfield handloaders — requires projectiles with a true .312 in diameter to match the barrel specifications of classic service and sporterized .303 British rifles, avoiding the accuracy loss associated with undersized .308-calibre alternatives.
• Medium to large game hunters — relies on a 150 grains soft-point design that delivers controlled expansion and high weight retention against game such as feral pigs, wild goats, and deer within typical hunting ranges under 300 to 400 yards.

Less suitable for: Standard .30-calibre rifles measuring .308 in diameter (such as .308 Winchester or .30-06 Springfield), where firing an oversized .312 in projectile creates dangerous chamber pressures; these setups require standard .308" component bullets instead. Furthermore, rifles with excessively worn surplus bores exceeding .314 in will achieve better bore engagement from heavier 174-grain projectiles or custom-cast bullets.