Underwood Xtreme Defender .357 Sig handgun ammunition (brand part no. 855) is built for shooters who carry this round for personal or home defense. Underwood backs this load with the quality control shooters expect from a name they already trust. At the heart of this load is the 65 gr bullet with an Xtreme Defender design, matched to the .357 Sig platform shooters already run. In our ammunition selection, this is the Underwood load built for that job.

Key Specifications

• The caliber is .357 Sig, one of the most carried, most available cartridges for the platform.
• The bullet weighs 65 gr, sized for the terminal performance this load is built around.
• The projectile is an Xtreme Defender design, engineered to drive tissue outward through hydraulic pressure rather than expanding.
• Muzzle velocity is rated at approximately 2100 fps, for authoritative energy on target at practical ranges.
• Each box holds 20 rounds, enough to work with before needing to reorder.
• Cases ship 10 boxes to a case, a useful case size for stocking a range or defensive supply.
• Cost works out to about $2.16 per round, affordable enough to shoot as much as you train.
• This is a centerfire cartridge, ignited by a replaceable primer rather than a rimfire priming ring.
• The Xtreme Defender bullet is Underwood’s licensed version of Lehigh Defense’s Fluid Transfer Monolithic design, using radial flutes to hydraulically drive tissue outward instead of expanding.
• Because the bullet doesn’t rely on expansion to work, it performs consistently through both bare and heavily clothed targets.

Frequently Asked Questions

How does the Xtreme Defender work without expanding? It uses Lehigh Defense’s licensed Fluid Transfer Monolithic design: radial flutes hydraulically drive tissue outward on impact instead of relying on a mushrooming cavity.

How many rounds come in a box? Each box holds 20 rounds of .357 Sig.

How fast does this .357 Sig load run? It’s rated at approximately 2100 fps at the muzzle, giving a sense of the energy and trajectory to expect.

Buy the Underwood Xtreme Defender .357 Sig 65 gr, 20-Round Box

Grab a case if you shoot it regularly, or a box to see how it patterns and cycles through your gun first. Order from our Lubbock, Texas gun shop and it ships fast to your door.