Underwood Ammo 452Underwood Ammo 452 Maximum Expansion 300Blackout 194gr Solid Monolithic 20 Per Box/10 Case

Underwood Ammo's 300 Blackout 194gr Maximum Expansion round brings Lehigh's proven hydraulic-expansion technology to subsonic and supers alike. Built on a solid monolithic platform, these rounds are engineered for hunters and shooters who demand deep penetration with decisive wound channels. The 194-grain weight strikes a balance suited to 300 Blackout's subsonic performance band, making this load practical for suppressed rifles, hunting applications, and close-to-medium range work where energy transfer matters.

Maximum Expansion ammunition is designed around a fundamental principle: expand where it counts. Rather than relying on impact with hard surfaces, these bullets use hydraulic energy to expand reliably when passing through soft tissue—the vital zone of your target. Once expanded, the razor-sharp petals maintain their full diameter, maximizing cutting surface and energy dump. This is different from traditional lead-core, jacketed bullets that tend to mushroom and lose diameter as they penetrate, reducing effectiveness. Because the expansion mechanism is fluid-dependent, you get consistent, predictable performance on game and in field conditions, not on dry media like drywall or bone.

The solid monolithic construction eliminates core-jacket separation concerns and provides structural integrity through the entire expansion and penetration sequence. Shooters working with suppressed 300 Blackout platforms, or those hunting in timber where close shots are the norm, will appreciate the straightforward, physics-based approach to stopping power. Each box contains 20 rounds; a 10-box case gives you 200 rounds of consistent, premium ammunition.

Key Features

• Lehigh Maximum Expansion technology—expands via hydraulic energy in soft tissue for reliable, large wound channels
• Solid monolithic bullet construction—no core-jacket separation, maximum structural integrity
• Razor-sharp, full-diameter petals maintain cutting surface throughout penetration
• 194-grain weight optimized for 300 Blackout ballistics
• 20 rounds per box; 10-box case (200 rounds total)

Specifications

Frequently Asked Questions

Will this ammo expand reliably on game?

Yes—Maximum Expansion technology is designed to expand via hydraulic energy when passing through soft tissue (the vital zone). It will not expand on dry materials like bone, wood, or drywall; expansion occurs in fluid-based mediums where it matters for terminal performance.

Is 194 grains a good weight for my 300 Blackout?

The 194-grain bullet weight is suited to 300 Blackout's subsonic and supersonic envelope. Check your rifle's manual or contact us to confirm compatibility with your specific platform and intended use (hunting, suppressed shooting, etc.).

What's the difference between monolithic bullets and traditional jacketed bullets?

Monolithic bullets are cast as a single piece of material, eliminating core-jacket separation. Traditional lead-core, jacketed bullets can separate under stress and tend to mushroom and lose diameter as they penetrate, reducing wound channel effectiveness. Lehigh's monolithic design maintains structural integrity and petals at full diameter throughout expansion.

How much ammunition is in a case?

Each case contains 10 boxes of 20 rounds each, for a total of 200 rounds of 300 Blackout ammunition.