John Nosler's Failed Moose Hunt and the Bullet It Created

A moose that wouldn't drop

In the fall of 1946, John Nosler was in the Canadian backcountry with a .300 H&H Magnum, one of the most respected big-game cartridges of the day. He put a well-placed shot into a bull moose. Nosler's own company history describes the animal as a "stubborn, mud-caked Canadian moose." It didn't go down.

The rifle was right. The cartridge was right. The shot was right. The problem was the bullet.

Nosler's account says the bullets he was using failed to penetrate deeply enough to reach the vital organs and kill quickly. Moose are large animals with heavy shoulders and thick hide. A bullet that comes apart near the surface spends its energy in the wrong place.

On the trip home, as the company tells it, Nosler started thinking about a bullet that would perform on any game and at any shot angle. That's a big ambition for a hunter driving back from a trip. He turned out to be serious about it.

The problem every hunting bullet faces

To understand what Nosler solved, it helps to know the two failure modes of hunting bullets at the time.

Full metal jacket bullets penetrate well, but they usually don't expand. They punch through and leave a small wound channel. Military use leaned on them for legal and practical reasons, but they're a poor choice for ethical hunting.

Soft-point hunting bullets expand, creating a larger wound channel. But expansion and penetration pull against each other. A soft point that opens fast, especially from a fast magnum, can break apart and lose too much mass to drive through heavy muscle and bone.

The .300 H&H made that second problem worse. High velocity on impact meant high stress on the bullet. Nosler wanted something that could expand readily at lower impact speeds yet stay intact at high ones. That's a hard pair of goals to satisfy with one piece of lead in one copper cup.

The idea: two bullets in one

Nosler's answer, which he settled on in 1947, was a dual-core bullet. Picture a copper jacket with a wall built across its middle, dividing it into two compartments. Each compartment holds its own lead core.

• The front core sits in the nose, ahead of the wall. It's free to mushroom on impact, which creates the wide wound channel hunters want.
• The rear core sits behind the wall. The partition protects it, so it's much more likely to hold its weight and keep the bullet driving forward after the front core has expanded or partly shed material.

That copper wall is the "partition," and it gave the bullet its name. It's a simple concept that's hard to make well. Nosler's early jackets were hand-made and lathe-turned, according to the company. Each one took time and skill, and none of it was mass production.

In the fall of 1947, the new bullet got its real test. Nosler and his friend Clarence Purdie each dropped a moose with a single shot. A year after the frustrating hunt, the design had answered the question that started it.

From a workshop to a company

In 1948, John Nosler founded the Nosler Partition Bullet Company in Ashland, Oregon, and began selling the bullets commercially. In 1958, the company moved to a 6,000-square-foot building in Bend, Oregon, the town most hunters associate with the Nosler name.

Making Partitions by hand couldn't scale. The company's timeline shows how Nosler worked through that:

• 1965: Nosler introduced the Zipedo bullet, made with an impact extrusion method John developed.
• 1969: The company became Nosler Bullets, Inc. Leupold & Stevens took partial ownership, which helped fund impact extrusion development.
• 1970: Impact extrusion was put to work on the Partition.
• 1974: Federal Cartridge Company loaded Nosler bullets in commercial ammunition for the first time.

That 1974 milestone matters to anyone who's bought a box of factory ammunition with "Partition" on the label. Federal introduced its Premium line of centerfire rifle and shotshell ammunition in 1977, according to Federal's company entry, and premium factory loads with Nosler bullets became a fixture on gun-store shelves.

The next generations

The Partition didn't end Nosler's ambitions. The company kept adding bullets that borrowed from its first idea:

• 1984: the Ballistic Tip. A polymer-tipped bullet with color-coded tips, built on the expansion and penetration of Nosler's Solid Base design.
• 2003: the AccuBond. Nosler describes it as combining Partition penetration with Ballistic Tip accuracy. It's a bonded design, a different way to hold a bullet together.

The family stayed involved. The company returned to family ownership in 1988 and became Nosler, Inc. in 1990. John R. Nosler was promoted to president in 2018. John A. Nosler, the man who stood over that moose in 1946, died in Bend on October 10, 2010, a date the company itself notes as 10/10/10.

Nosler later branched into cartridges of its own, including the 26 Nosler in 2014 and the 28 Nosler in 2015.

Why the .300 H&H made the problem visible

It's worth lingering on the rifle Nosler carried. The .300 H&H Magnum was a fast, powerful cartridge, and that was exactly what exposed the weakness in ordinary bullets. At close range, a fast bullet hits hard and decelerates violently. A soft point that holds together fine at a deer-rifle velocity can come apart under that stress.

Hunters had a dilemma. Use a tougher, harder bullet and it might not open at long range, where it arrives slower. Use a softer bullet and it might come apart up close. A bullet that only works within a narrow window of distances isn't much use to a hunter who can't choose how far away the moose will be.

That's the real genius of the partition design. It doesn't try to make one core do both jobs. The front core is allowed to be soft and eager to expand. The rear core is protected and does the penetrating. The bullet doesn't have to be a compromise, because it's two bullets with two jobs.

How the idea spread

Nosler's design became a reference point for controlled-expansion hunting bullets. Later, other makers approached the same goal with different methods. Bonded bullets fuse jacket and core so they stay together, the approach Nosler itself took with the AccuBond. Monolithic bullets, made of solid copper or copper alloy, skip the lead core altogether and rely on petals that peel back.

All of them answer the question Nosler asked in 1946: how do you make a bullet that opens up and still gets where it needs to go? The Partition's answer is still on store shelves because, for many hunters, it still works.

Myth vs fact

Myth: the Partition is "obsolete" because newer bullets exist. Fact: newer bonded and monolithic bullets compete with it, but the Partition is still widely loaded and used for big game. "Obsolete" isn't the right word for a design that's still on shelves.

Myth: John Nosler invented controlled expansion. Fact: hunters and bullet makers worked on the problem long before, and other designs addressed it in other ways. Nosler's dual-core approach became one of the most influential.

Myth: Partitions are only for magnum cartridges. Fact: the problem they solve, holding together at high impact velocity, is most acute with fast cartridges, but Partition-loaded ammo is sold in a wide range of chamberings. Check current catalogs.

What it means for your ammo choice

The Partition's lesson is that a hunting bullet is a compromise between expansion and penetration, and the right balance depends on the game and the cartridge.

• Deer at moderate ranges from a standard cartridge. A conventional soft point often works well. Our deer hunting ammo guide lays out common choices by caliber.
• Elk, moose or bigger, especially from magnums. Controlled-expansion bullets like the Partition, bonded designs or monolithic copper bullets are common choices because they're built to hold together.
• Shot angles you can't predict. This was Nosler's original goal: a bullet that works when the angle isn't perfect.

Ammunition Depot's big game hunting section and caliber pages like .30-06 Springfield and .300 Win Mag are good places to browse controlled-expansion loads. Read the box for bullet type and the maker's recommended game.

The long shadow of one hunt

Most hunters who've had a bullet fail them just buy a different box next year. John Nosler went home and built a new kind of bullet with his own hands, and then built a company to make it.

It started with one moose in 1946. Today, every hunter weighing "expansion vs penetration" on a box label is working inside the question he asked on the drive home.

Editorial note: This is an independent editorial overview built from manufacturer specifications, retailer listings and published sources. We have not performed hands-on testing of the products discussed, and nothing here is a performance guarantee. Verify specifications, compatibility and the law where you live.

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