Underwood 10mm Auto 155gr XTP JHP ammunition is packed 20 rounds to the box and loads Hornady’s eXtreme Terminal Performance bullet (Underwood part no. 232). Underwood pairs the Hornady XTP with its own load design, and the maker describes the bullet as built for deep terminal penetration, accuracy and controlled expansion. At 155 grains it is the lighter end of the 10mm range, with a published 1500 fps at the muzzle. Nickel-plated brass cases and flash-suppressed powder round out a load aimed at personal defense and medium game.

Key Specifications

• The cartridge is 10mm Auto, a high-pressure semi-auto round with room to push light bullets fast.
• The bullet weighs 155 grains, a lighter weight that trades some mass for speed.
• The bullet is a Hornady XTP jacketed hollow point, designed for controlled expansion and deep penetration.
• Published muzzle velocity is 1500 fps, a supersonic figure that helps the hollow point expand.
• Published muzzle energy is 775 ft-lbs, the number Underwood lists for this load.
• The G1 ballistic coefficient is 0.14, a modest figure typical of a blunt handgun bullet.
• Sectional density is 0.14, which Underwood publishes as a measure of how the bullet’s mass is spread over its frontal area.
• Cases are nickel-plated brass, which feeds smoothly and resists corrosion.
• Underwood lists the load as suppressor safe, so it works in a suppressed 10mm.
• Each box holds 20 rounds, a practical count for a carry magazine and a spare.

Frequently Asked Questions

What bullet does this 155-grain 10mm load use? It uses the Hornady eXtreme Terminal Performance (XTP) jacketed hollow point, which Underwood describes as designed for deep terminal penetration, accuracy and controlled expansion.

How fast is the 155gr XTP load? Underwood lists a muzzle velocity of 1500 fps and 775 ft-lbs of muzzle energy.

Is the powder flash suppressed? Yes. Underwood uses flash-suppressed powder in its rounds so your vision is not compromised if you have to fire in low light.

Buy the Underwood 10mm Auto 155gr XTP Jacketed Hollow Point

Light bullet, high speed, proven expansion: this is the 10mm load for shooters who want velocity from a Hornady hollow point. Add it to your order from Underwood, part of our handgun ammunition range at our Lubbock, Texas gun shop, and it ships fast to your door.