Underwood Ammo

About Underwood Ammo

Kevin Underwood founded Underwood Ammo in 2013 after identifying a significant gap in the ammunition market as a professional target shooter and avid hunter.

The company was established in Sparta, Illinois with a mission to create "better ammunition at a reasonable price" - specifically ammunition that was faster, cleaner, and left less residue on firearms.

Starting as a small operation, Underwood Ammo grew primarily through word-of-mouth recommendations and gained recognition from world-class shooters using their products.

The company has made a significant impact on the industry by introducing innovative Fluid Transfer Monolithic (FTM) bullet technology in partnership with Lehigh Defense.

Today, Underwood Ammo remains committed to manufacturing 100% of their products in the USA, including packaging, and announced a major expansion with a new $41 million Georgia facility in 2025.

Popular Underwood Ammo Features

Fluid Transfer Monolithic (FTM) Design

• Revolutionary bullet technology that transfers energy through fluid displacement rather than traditional expansion for maximum wound cavity creation.

Solid Copper Construction

• Ensures consistent performance through barriers like wallboard, sheet metal, and automotive glass while maintaining structural integrity.

Hard Cast Bullets

• Engineered with Brinell hardness of 21, making them safe for polygonal rifling and nearly 4x harder than soft lead bullets.

Premium Components

• Uses only high-quality brass, primers, and powders with rigorous testing and validation processes for consistent performance.

Flash-Suppressed Powder

• Maintains visibility in low-light conditions while providing clean burning properties that reduce residue on firearms.

100% American Manufacturing

• All manufacturing, including packaging, is completed in the United States with tight quality control standards.

Best-Selling Underwood Ammo Products

Xtreme Defender

• The most popular personal defense ammunition optimized for up to 18" penetration with enormous permanent wound cavity in multiple calibers.

Xtreme Penetrator

• Designed for maximum penetration that always exceeds 18", making it ideal for woods use and bear defense applications.

Xtreme Hunter

• Hybrid design combining Defender and Penetrator features to provide excellent wounding with deep penetration for hunting applications.

10mm Auto Ammunition

• Available in various configurations including 140gr Xtreme Penetrator and 200-220gr Hard Cast, popular for bear defense and hunting.

Hard Cast Ammunition

• Available in various calibers with black cherry coating, designed for deep penetration and safe use in polygonal rifling.

9mm Xtreme Defender

• Offered in 68gr and 90gr options, both delivering similar performance through bare gel or 4 layers of denim for personal defense.

Specialty Calibers

• Hard-to-find calibers including .480 Ruger, .475 Linebaugh, .454 Casull, .458 SOCOM, and .45-70 Government for specialized applications.

Match Grade Ammunition

• Precision ammunition designed for competitive shooting and target applications with consistent accuracy and performance.

Popular Uses for Underwood Ammo

Self-Defense and Personal Protection

• Xtreme Defender series provides optimal stopping power for concealed carry, home defense, and personal protection applications.

Law Enforcement and Military

• Trusted by police departments and federal agencies for duty ammunition and tactical applications, with 10% military discount available.

Hunting Applications

• Effective for medium to large game hunting, including deer, elk, moose, and dangerous game like bears with ethical clean kills.

Bear Defense and Woods Use

• Xtreme Penetrator rounds are specifically recommended for bear country protection and dangerous game encounters requiring deep penetration.

Competitive and Target Shooting

• Match grade ammunition provides consistent accuracy and reliable performance for competitive shooting sports and precision training.

Underwood Ammo FAQs

QUESTION: Can I shoot Underwood Hard Cast bullets in my Glock with polygonal rifling?
ANSWER: Yes, all Underwood Hard Cast ammunition is safe for polygonal rifling due to their Brinell hardness of 21, nearly 4x harder than soft lead.

QUESTION: Are Underwood 10mm loads +P ammunition?
ANSWER: No, all Underwood 10mm loads are within SAAMI pressure specifications and are not +P rated.

QUESTION: What's the difference between Xtreme Defender and Xtreme Penetrator ammo?
ANSWER: Xtreme Defender provides up to 18" penetration with maximum wound volume, while Xtreme Penetrator always exceeds 18" penetration for dangerous game.

QUESTION: Do I need to upgrade my recoil spring for Underwood 10mm ammo?
ANSWER: No inherent need to upgrade, only recommend heavier springs (20-22lb) if experiencing feeding issues or stovepipes.

QUESTION: What Underwood 10mm load is best for bear defense?
ANSWER: The primary recommendation is 140gr Xtreme Penetrator, with 200-220gr Hard Cast as the secondary option.

QUESTION: Is Underwood ammunition accurate for target shooting?
ANSWER: Yes, Underwood ammunition is known for consistent accuracy and precision across all product lines.

QUESTION: Are military and law enforcement discounts available on Underwood ammo?
ANSWER: Yes, a 10% discount is available for active, retired, and veteran military and law enforcement personnel.

QUESTION: Are Underwood cartridge cases reloadable after firing?
ANSWER: Yes, Underwood uses high-quality brass cases that are suitable for reloading applications.

QUESTION: What makes Underwood Ammo different from other ammunition brands?
ANSWER: Underwood's innovative Fluid Transfer Monolithic bullet technology and 100% American manufacturing set them apart from competitors.

QUESTION: Does Underwood offer bulk ammo pricing for volume purchases?
ANSWER: Yes, both retail and wholesale pricing options are available for different volume requirements.