Underwood Ammo Ua 817 9Mm +P+ 90Gr Xtreme Defender 20/10
$26.06
The Underwood Ammo 9mm +P+ 90gr Xtreme Defender is a modern, lead-free defensive round built for serious self-defense and duty carry. Loaded to +P+ pressure levels, this copper-based projectile launches at 1550 feet per second with 480 foot-pounds of muzzle energy—enough velocity and impact to make a measurable difference when it counts. If you're running a compact 9mm, a full-size duty gun, or anything in between, Underwood's engineering gives you a cartridge that doesn't compromise on penetration, expansion, or reliability.
The 90-grain bullet design balances velocity with sectional density (0.102 SD), meaning the narrow profile cuts through barriers while maintaining the structural integrity needed for consistent performance. At just under 1550 fps, this round stays supersonic downrange, and it's rated safe for use in suppressed firearms—a smart move if you're running a can. The nickel-plated brass cases are reloadable and non-corrosive, so hand loaders can recover brass and reload once fired.
New production ammunition from Underwood, packaged 20 rounds per box. Each round is boxer-primed and ready to load into any 9mm chamber rated for +P+ pressure. This isn't the round you practice a thousand times with; it's the one you keep loaded for when hesitation isn't an option.
Key Features
- Lead-free copper construction for cleaner shooting and range compliance
- +P+ pressure loading delivers high velocity and impact force
- 1550 feet per second muzzle velocity, supersonic performance
- Designed specifically for self-defense and defensive applications
- Nickel-plated brass cases—reloadable and non-corrosive
- Safe for use in suppressed firearms
- Boxer-primed for standard reloading compatibility
Specifications
| Caliber | 9mm Luger +P+ |
| Bullet Weight | 90 grains |
| Bullet Diameter | 0.355" |
| Bullet Material | Copper (lead-free) |
| Muzzle Velocity | 1550 feet per second |
| Muzzle Energy | 480 foot-pounds |
| Sectional Density | 0.102 |
| Ballistic Coefficient (G1) | 0.087 |
| Case Type | Nickel-plated brass, reloadable |
| Primer | Boxer, non-corrosive |
| Rounds per Box | 20 |
| Suppressor Safe | Yes |
| Manufacturer | Underwood Ammo |
Frequently Asked Questions
Is this 9mm +P+ ammo safe to use in my gun?
The Xtreme Defender is loaded to +P+ specifications, which means your firearm must be specifically rated for +P+ pressure. Check your gun's manual or contact the manufacturer to confirm compatibility before shooting. Most modern duty and defensive pistols are rated for +P+, but older or compact designs may not be. When in doubt, don't use it.
Can I use this ammunition in a suppressed firearm?
Yes, Underwood explicitly rates the Xtreme Defender safe for suppressed use. The 1550 fps velocity is supersonic, so you'll still get the crack downrange, but the ammunition is engineered to function reliably in a suppressed platform.
What's included in each box?
Each box contains 20 loaded rounds of 9mm +P+ ammunition, packaged as "20/10" (20 rounds, 10 per box configuration). Brass cases are included and can be reloaded after firing.
Is this a good choice for self-defense?
The Xtreme Defender is specifically designed for self-defense applications. The lead-free copper bullet, high velocity (1550 fps), and solid sectional density (0.102) are all engineered for consistent performance in defensive scenarios. That said, ammunition is only part of the equation—training and shot placement are equally critical. Many shooters also practice and qualify with their carry ammo before relying on it.
