Underwood Ammo Xtreme Penetrator Platinum Edition 10mm Auto ammunition (brand part no. 941) loads a 140-grain solid copper bullet for shooters who need a round built to drive straight through, not open up. Underwood machines the Xtreme Penetrator as a monolithic, non-expanding copper bullet, so it holds its shape and travels in a straight line through barriers instead of losing mass and energy to expansion. That construction gives it a sectional density of 0.125, an efficient weight-to-frontal-area ratio that keeps the bullet driving forward on target. Loaded in nickel-plated, boxer-primed brass, the round is built for deep-penetration work where a hunter or defender needs the shot to reach past bone, muscle, or a barrier. For 10mm Auto shooters who value penetration over expansion, this is Underwood’s dedicated load among its handgun ammunition.

Key Specifications

• The chambering is 10mm Auto, giving the platform enough case capacity for genuinely high velocity.
• The bullet weighs 140 grains, a lighter weight that Underwood uses to push velocity well above standard loads.
• The bullet is a solid, monolithic copper design, built to resist deformation rather than expand.
• Because it does not expand, the bullet drives straight through targets and barriers instead of shedding mass and energy early.
• Muzzle velocity reaches roughly 1500 fps, exceptionally fast for a 10mm Auto handgun load.
• Muzzle energy is approximately 700 ft-lbs, backing up that velocity with real striking power.
• The bullet carries a sectional density of 0.125, an efficient ratio that favors deep penetration.
• The case is nickel-plated, boxer-primed brass, reloadable and corrosion resistant.
• The bullet is lead-free copper, avoiding lead fouling and exposure at the range.
• Each box holds 20 rounds, loaded and ready for the range or a duty pistol.

Frequently Asked Questions

Does the Xtreme Penetrator bullet expand on impact? No, it is a solid monolithic copper design built specifically to resist expansion and drive straight through targets and barriers.

Is this load safe to fire through a suppressor-equipped pistol? Yes, Underwood rates this loading safe for use with a suppressor-equipped host pistol.

How many rounds come in a box? Each box holds 20 rounds of 10mm Auto Xtreme Penetrator ammunition.

Buy Underwood Xtreme Penetrator 10mm Auto 140gr

Some situations call for a bullet that keeps driving instead of opening up, and the Xtreme Penetrator is built exactly for that job. Pair it with a duty or defensive 10mm Auto pistol and trust the straight-line penetration when it counts. Order from our Lubbock, Texas gun shop and it ships fast to your door.