what primers does underwood 357mag use

Name: Underwood XTP Ammo 357 Mag, 158 Grain, Jacketed Hollow Point, 20/Box
Brand: Underwood
SKU: 177860
Price: 21.49 USD
Availability: InStock
Rating: 5.00 (5 reviews)

They use small pistol primers 🎯❗️

Underwood Ammunition utilizes Small Pistol Magnum primers for their .357 Magnum loads. Because Underwood loads their ammunition to maximum, full-power pressures (often using slow-burning, flash-suppressed ball powders like H110 or W296), a magnum-strength primer is required to ensure consistent and complete ignition of the powder.

Underwood Ammunition utilizes Small Pistol Magnum primers for their .357 Magnum loads.Because they load their ammunition to maximum velocities (often using slow-burning ball powders to achieve top-tier energy), magnum primers are standard to ensure consistent and complete powder ignition.Important Note for Reloaders:If you are asking this question to reload or duplicate Underwood’s high-performance ammunition, be aware that you cannot swap magnum and standard primers interchangeably without altering the ballistic profile. Always follow published load data using the exact components listed by the powder manufacturer.

Hi Craig, Underwood XTP Ammo in .357 Magnum, specifically the 158 Grain variant, typically uses Small Pistol Magnum Primers. Using small pistol magnum primers is crucial for achieving optimal performance with this ammunition. They help ensure reliable ignition and consistent performance, especially under varying conditions. Stay safe & have a great day!

Hi Craig and welcome. Small pistol primers as shown in the 2nd picture here (just change the 9 to a c after the www.) : https://www.9heaperthandirt.com/underwood-ammo-.357-magnum-ammunition-20-rounds-xtp-jhp-158-gr/fc-816874020446.html --------- Cheers and stay safe!

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Underwood XTP Ammo 357 Mag, 158 Grain, Jacketed Hollow Point, 20/Box - Nickel Plated Brass Casing

Questions & Answers (1) Reviews 5 out of 5

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This ammunition is new production non-corrosive in boxer primed reloadable brass cases.

This ammo is for cartridge size .357 Mag.
The bullet is made from Brass.
The diameter (caliber) of this bullet is 0.357.
This bullet weighs 158 grains.
This bullet leaves the barrel at 1500 feet per second.
The ammo case is made from Nickel Plated Brass.
This ammo is a proven round for hunting.
The bullet in this product does contain lead.
This round is designed to be supersonic and travels faster than the speed of sound.
The muzzle energy of this ammo is 790 ft lbs.
This product has been designed to be an effective choice for the ultimate in self-defense applications.
The bullet in this product has a Sectional Density (SD) of 0.177101652986124. SD is the ratio of an object's mass to its cross sectional area with respect to a given axis. It conveys how well an object's mass is distributed (by its shape) to overcome resistance along that axis.
This ammo IS SAFE to use in a suppressor.
The bullet in this ammo has a ballistic coefficient (G1) of 0.206 - Generally the higher the coefficient the more stable the projectile will be in flight.
Each box of ammo contains 20 loaded pieces of ammunition.
This ammo is manufactured by Underwood Ammo

Product Information

Caliber/Gauge

357 Magnum

Application

Performance/Protection

Box Qty

Bullet Weight

158gr

Casing

Nickel Plated Brass

Bullet Type

Hollow Point

PPR

$1.07/round

Product Information

Caliber/Gauge

Application

Box Qty

Bullet Weight

Casing

Bullet Type

PPR

$1.07/round

Product Information

Caliber/Gauge

Application

Box Qty

Bullet Weight

Casing

Bullet Type

PPR

$1.07/round

Product Information

Caliber/Gauge

Application

Box Qty

Bullet Weight

Casing

Bullet Type

PPR

$1.07/round

Product Information

Caliber/Gauge

Application

Box Qty

Bullet Weight

Casing

Bullet Type

PPR

$1.07/round

$23.99

$21.49

You Save: $2.50

Price Per Round: $1.07

Financing Available

MFG: Underwood

Model: 124

Bud's Item Number: 177860

UPC: 816874020446

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Retail Store Availability

In-Store Purchase Only
Lexington, KY	Not in store
Greenville, KY	Call for availability
Sevierville, TN	Call for availability

5 Reviews

Underwood XTP Ammo 357 Mag, 158 Grain, Jacketed Hollow Point, 20/Box

This ammunition is new production non-corrosive in boxer primed reloadable brass cases.

This ammo is for cartridge size .357 Mag.
The bullet is made from Brass.
The diameter (caliber) of this bullet is 0.357.
This bullet weighs 158 grains.
This bullet leaves the barrel at 1500 feet per second.
The ammo case is made from Nickel Plated Brass.
This ammo is a proven round for hunting.
The bullet in this product does contain lead.
This round is designed to be supersonic and travels faster than the speed of sound.
The muzzle energy of this ammo is 790 ft lbs.
This product has been designed to be an effective choice for the ultimate in self-defense applications.
The bullet in this product has a Sectional Density (SD) of 0.177101652986124. SD is the ratio of an object's mass to its cross sectional area with respect to a given axis. It conveys how well an object's mass is distributed (by its shape) to overcome resistance along that axis.
This ammo IS SAFE to use in a suppressor.
The bullet in this ammo has a ballistic coefficient (G1) of 0.206 - Generally the higher the coefficient the more stable the projectile will be in flight.
Each box of ammo contains 20 loaded pieces of ammunition.
This ammo is manufactured by Underwood Ammo