Underwood 9mm For Sale

Most 9mm catalogs are organized by bullet weight. Underwood's is organized by pressure. Nearly every load on this page carries a +P or +P+ headstamp, and the bullet weights run from 68 grains up to 147, which is a wider spread than almost any other manufacturer offers in the caliber. That range exists because Underwood is really selling two different theories of terminal performance under one brand.

The conventional side is what you would expect: 115, 124, and 147 grain jacketed hollow points, including a 147 grain loaded with Hornady's XTP bullet for controlled expansion. The other side is monolithic. The Xtreme Defender and Xtreme Penetrator bullets are machined from solid copper with cutting flutes instead of a hollow cavity, and they do not expand at all. They displace tissue hydraulically as they drive forward, which means they do not have a velocity threshold to fail below. That is why the monolithic loads weigh so little: copper is less dense than lead, so a 90 grain solid occupies the same space a 124 grain jacketed bullet would.

Understanding the pressure labels

• Standard pressure: SAAMI specifies 35,000 psi for 9mm Luger. The 124 grain JHP here is loaded to it.
• +P: SAAMI does publish a standard for this, at 38,500 psi. Most modern service pistols are rated for +P, though it accelerates wear.
• +P+: there is no SAAMI standard for +P+. It is an industry term originating with law enforcement contracts, and there is no published pressure ceiling behind it. Check your pistol manufacturer's guidance before running it, and expect faster spring and frame wear if you shoot it regularly.
• Match the bullet to the job: monolithic solids penetrate deep and consistently through barriers. Conventional JHP expands and dumps energy faster. Neither is universally better.
• Feed-test before you carry. The fluted monolithic profiles are not the shapes most feed ramps were designed around.

More Underwood ammo

• Underwood Ammunition - the full catalog across every caliber Underwood loads
• Underwood 10mm Ammo - full-power loads in the caliber Underwood is best known for
• Underwood 380 ACP Ammo - the same monolithic approach in a pocket cartridge

Related 9mm ammo

• 9mm Ammo - the full catalog across every brand and bullet type
• 9mm 147 Grain Ammo - every 147 grain load we stock
• 9mm Subsonic Ammo - for suppressed shooting
• Bulk 9mm Ammo - practice ammo at the lowest cost per round

Defensive 9mm loads worth cross-shopping

• Black Hills HoneyBadger 9mm Ammo - the other major fluted monolithic solid, and the closest direct comparison to Xtreme Defender
• Federal HST 9mm Ammo
• Speer Gold Dot 9mm Ammo
• Hornady Critical Defense 9mm Ammo

Reviews and buying guides

• Underwood Ammo Review - our full assessment of the brand
• Exotic 9mm Ammo Types - where monolithic solids fit in the wider 9mm landscape
• Best 9mm Home Defense Ammo
• Best 9mm Ammo
• Best 9mm Subsonic Ammo
• Speer Gold Dot 9mm Review
• Hornady Critical Defense 9mm Review
• Hornady Critical Duty 9mm Review
• Federal Hydra-Shok 9mm Review
• 9mm vs 45 ACP
• 9mm vs 40 S&W

Compare velocity and energy across every 9mm load we carry in our 9mm ballistics database, or track cost per round with our 9mm price tracker.