Underwood Ammo XTP .357 Magnum 125-grain Jacketed Hollow Point ammunition (brand part no. 123) pairs full Magnum velocity with a bullet built to expand reliably across a wide range of impact speeds. Underwood Ammo loads Hornady’s XTP, a jacketed hollow point that has earned a following among revolver shooters for controlled expansion and consistent weight retention. Nickel-plated brass cases feed and extract smoothly while resisting corrosion, so the load stays reliable whether it rides in a duty holster or a truck gun. This is a serious .357 Magnum defensive round for shooters who want proven terminal performance behind every trigger pull.

Key Specifications

• The chambering is .357 Magnum, delivering high velocity and stopping power from revolvers and lever guns alike.
• The bullet weighs 125 grains, a fast-moving weight known for dramatic expansion in .357 Magnum.
• The bullet is Hornady’s XTP jacketed hollow point, a design purpose-built for controlled expansion.
• A serrated jacket and internal cannelure lock the core in place, so the XTP expands predictably and retains weight instead of fragmenting.
• Cases are made of nickel-plated brass, resisting corrosion and cycling smoothly through revolver cylinders.
• Each round costs about $1.14, in line with premium defensive .357 Magnum ammunition.
• Each box holds 20 rounds, enough to load several cylinders for practice and carry.
• A full case packs 10 boxes for 200 rounds total, convenient for shooters who go through a defensive load in bulk.
• At a shipping weight of about 0.67 pounds per box, it is easy to keep spares on hand.

Frequently Asked Questions

What makes the XTP bullet different from a standard hollow point? The XTP uses a serrated jacket and cannelure to control how the bullet expands, giving it consistent performance across a wide range of velocities.

Is this load suitable for self-defense? Yes, the 125-grain XTP is a widely trusted .357 Magnum defensive loading known for reliable expansion and weight retention.

How many rounds come in a full case? A case contains 10 boxes of 20 rounds each, for 200 rounds total.

Buy Underwood XTP .357 Magnum 125gr Ammo

A dependable .357 Magnum defensive round is worth having on the shelf whether it rides in a holster or a nightstand, and the XTP has decades of proven performance behind it. Shop our handgun ammunition lineup and keep your revolver ready. Order from our Lubbock, Texas gun shop and it ships fast to your door.