The "World's Deadliest Bullet" Turns 60
January 04, 2011
The year was 1947, and a truck driver from Oregon was enjoying one of his great passions--hunting moose in Canada. The rifle he carried that day was an old favorite, a Winchester Model 70 in .300 H&H Magnum. Because he was an avid handloader, the cartridges in the magazine of his rifle were loaded with the very best bullets available at the time.
Opportunity knocked on the fourth day of the hunt, and after a very long stalk, the hunter managed to get within about 50 yards of a magnificent bull without being detected. As the moose stood there behind a screen of willows with its polished antlers gleaming in the sunlight, the hunter shouldered his rifle and plastered the crosshairs of the Lyman Alaskan 4X scope tight behind the shoulder for a classic lung shot. As he did so, another moose he had shot the year before with that very same rifle flashed across his mind. Nothing but the shoulder of the animal had been exposed to view as he fired, and when his 180-grain bullet struck heavy bone, it went to pieces and failed to penetrate to the vitals.
Over the years, Nosler has introduced other premium bullets with different designs, but it all started in 1947 with the Partition. Left-to-right are: Partition, Ballistic Tip, AccuBond, E-Tip bullets.
That 1946 hunt might have had a very unhappy ending had the hunter not managed to end the affair by getting in three quick follow-up shots before the moose could escape wounded. The bullet he used was the very best available at the time, but it obviously was not good enough.
When aiming at the 1947 moose, the hunter had a clear shot at its lung area, and that's where he placed his first bullet. The bull had just emerged from a wallow with its body covered by a thick layer of mud, and this along with the fact that impact velocity of a bullet fired from the .300 Magnum at 50 short paces was quite high caused the bullet to blow up on the surface with nothing more than tiny fragments of lead and copper reaching a short distance inside.
The hunter was a strong believer in practicing with his Model 70 a lot during the off-season, and this familiarity with the rifle along with the fact that he was a crack shot enabled him to get off the three remaining rounds in the magazine of his rifle and then reload and get off two additional shots. That was enough to put the animal down for the final count. An autopsy revealed that all six bullets had struck vital areas, but not a single one had completely penetrated both lungs of the animal. Several had literally exploded on its mud-caked hide.
The trip back to Ashland, Oregon, was quite long, and that gave our hunter plenty of time to think about the important characteristics a big-game bullet should have. Ideally, it would be capable of expanding on deer-size game at long range where impact velocity is low, but it would also have the ability to penetrate deeply and retain a very large percentage of its initial weight when impacting larger game, such as moose and elk, at close range where impact velocity is high, even when the bullet strikes heavy bone.
After sketching out a number of possible designs on paper, he finally hit on the idea of two bullets in one--a thin jacket up front for reliable expansion at low impact velocities but with front and rear lead cores separated with an expansion-arresting partition that would allow the bullet to retain enough of its original weight to punch though the shoulders of a moose at close range.
Soon after returning home, the hunter headed to a shed located behind his house where he used a lathe to turn a section of copper rod down to .30 caliber, turning cavities in both ends. Stopping short of drilling the hole all the way through left a copper wall, or partition, separating the front and rear cavities of the hollow rod. The cavities were then filled with lead, and the short piece of rod was final-shaped in several homemade dies to produce an idea wrapped in a rather crude bullet. Those first few 180-grain bullets were not pretty, but as the next hunt would prove, they worked far better than any bullet our hunter had ever tried before.
The next year (1948), our hunter and Clarence Purdy, who would later design the Bonanza Co-Ax reloader and start his own reloading equipment company, journeyed north for another moose hunt. This time around, a supply of ammunition loaded with the homemade bullets was stowed in their duffel bags.
Layne took this record-book caribou with one shot at 366 yards with a Partition bullet made by John Nosler back in the 1940s.
As fate would have it, Purdy used a Model 70 in .30-06 to take the first moose with a single shot. Determined to subject the bullet to the toughest test possible, its designer and maker waited patiently until he got a shot at a bull from extremely close range. One shot to the shoulder was all it took.
Both bullets fired by the hunters had expanded to a large frontal diameter for maximum tissue damage and energy transfer, but equally important, they had retained enough of their original weight to allow them to penetrate to the offside hide of the moose. The rest, as they say, is history.
If you have taken as much game through the years as I have with Nosler Partition bullets, you knew at the beginning of this story that its star is John Nosler. John ran his first advertisement in 1948, and four years later he discovered that his bullet could be made easier and better by starting with copper tubing rather than solid rod and by using a turret lathe for profiling the jackets. After the tubing was cut into short lengths, a partition was formed inside by a huge 40-ton punch press. After front and rear lead cores were inserted manually, the bullet was formed to its final shape by precision-machined dies in several other presses.
The very first Partition bullets were hollowpoints, but Nosler found that expansion at low impact velocities improved when the lead core was exposed at the nose. Those first bullets were .30 caliber in 150- or 180-grain weights and were offered in 50-count boxes for $5, which was about the same price as 100 bullets offered by other companies.
In the beginning, many hunters considered that too much to pay, but it wasn't long before word spread that the bullets were well worth the price. And their cost was insignificant compared to the tab for a good hunt.
Nosler was a shrewd promoter of his bullets; he made sure that Jack O'Connor, Elmer Keith, Warren Page, and other writers of the day kept a good supply on hand. In Lucky Bawana, Tex
as oil tycoon and famous hunter Herb Klein described the Partition as, "...the world's deadliest bullet."
John Nosler designed the Partition bullet in the 1940s for big-game hunting.
The Partition bullet underwent another change during the mid-1970s when copper tubing of uniform hardness became extremely difficult to find. Suddenly, a bullet that once held onto its jacket forward of the partition during expansion was shearing off at that point. Retained weight remained about the same, but frontal diameter decreased dramatically when that happened.
If that alone was not bad enough, accuracy was not as good as it had been, and prices of the often-inferior material began to rapidly escalate. The use of gilding metal wire composed of copper and zinc proved to be the answer, and the same material is used today.
In a nutshell, machines cut the wire to the desired length and then bump each piece to the correct diameter in precision dies. The front and rear cavities are formed into the jacket by a 60-ton press. Other manufacturing steps complete the shape and finish the diameter of the bullet before it is polished, inspected, and packaged for shipment to hunters all over the world.
The Nosler Partition bullet is now available in 14 calibers and 36 weights, ranging from the 60-grain version for those who use cartridges such as the .223 Remington and .220 Swift on deer to a 300-grain version for the .45-70 Government cartridge. In addition to being offered as a reloading component, it is also available in factory ammo loaded by Winchester, Weatherby, Federal, and Norma.
Other premium-grade bullets are available today, but the Partition still is, and may always be, the benchmark by which hunters judge and compare the performance of other bullets made for shooting big game.