Underwood Ammunition For Sale

Nearly every cartridge in the American catalog is loaded below what it was designed to do. Manufacturers build to the middle of the pressure envelope because it is safer across the widest range of firearms, easier on tooling, and cheaper to insure. The 10mm Auto is the most famous casualty of that logic, downloaded so far from Jeff Cooper's original spec that a new cartridge, the 40 S&W, was carved out of the compromise. Underwood exists because a segment of shooters never accepted the trade.

The Illinois loader has built its entire identity on loading to the top of spec and, where an accepted standard exists for it, past it. That shows up three different ways across the catalog: monolithic solid copper defensive bullets that cut rather than expand, hard cast lead loads built for straight-line penetration in the woods, and conventional jacketed hollow points driven considerably faster than the factory equivalent.

Three families, three jobs

• Xtreme Defender and Xtreme Penetrator: machined solid copper with cutting flutes instead of a hollow cavity. They do not expand, so they do not have a velocity threshold to fail below. Lighter than jacketed bullets of the same profile because copper is less dense than lead.
• Hard cast: lead alloyed for hardness and cast with a wide flat nose. No expansion, maximum penetration through bone and hide. This is the woods and bear-country side of the catalog.
• JHP and XTP: conventional expanding bullets, including Hornady's XTP, loaded hotter than the factory version of the same projectile.
• Know your pressure labels. SAAMI publishes a +P standard for some cartridges and none at all for others, and there is no SAAMI +P+ standard for any of them. Check what your firearm is rated for before running high-pressure ammunition through it.

Shop Underwood by caliber

• Underwood 10mm Ammo - the flagship, loaded to original full-power spec in JHP and heavy hard cast
• Underwood 9mm Ammo - the deepest lineup, from 68 grain monolithic to 147 grain XTP in +P and +P+
• Underwood 380 ACP Ammo - high-pressure and monolithic loads for pocket pistols

Other premium and specialty loaders

• Black Hills Ammunition - the HoneyBadger line uses a comparable fluted monolithic design
• Barnes Ammo - the original all-copper expanding bullet company
• Speer Ammo - Gold Dot, the bonded defensive benchmark
• All Ammo Brands - every manufacturer we stock

Reviews and buying guides

• Underwood Ammo Review - our full assessment of the brand
• Best 10mm Ammo for Bear Defense - where the hard cast loads earn their keep
• Exotic 9mm Ammo Types - how monolithic solids compare to conventional JHP
• Best 380 Self Defense Ammo
• Best Caliber for Concealed Carry