January 04, 2011
By G&A Staff
You don't have to be an Olympic shooter to appreciate Eley's excellent rimfire ammunition.
By Dick Metcalf
Eley Ltd. of Birmingham, England, manufacturers the finest, most accurate rimfire ammunition in the world. Want proof? The Eley TenEx brand entered world competition at the Tokyo Olympics in 1964, where it won all the Gold and Silver medals in all the .22 LR pistol and rifle events. At the 2000 Olympics in Sydney, Australia, every firearm pistol medal was won by Eley TenEx. Of the 60 medals awarded in international smallbore rifle competition worldwide during the 2003 World Cup Competition season, Eley's top-line TenEx Ultimate EPS .22 LR load won 33--three times more than Eley's nearest competitor and seven times more gold medals than any other manufacturer. At the 2004 Olympics in Athens, Greece, Eley TenEx took nine of the possible 15 medals possible--three times more than its nearest competitor.
Eley has applied its 50-plus years of high-performance rimfire technology to the newly introduced .17 Mach2 cartridge.
In 2004 Eley applied its high-performance rimfire technology to the new .17M2 cartridge and introduced the 2100 fps Eley 17 Mach2, featuring a blue-tipped Hornady 17-grain V-Max bullet and the same patented Eleyprime System Technology as TenEx itself. Is it as good? I bumped into Dieter Anschutz at the 2004 NRA Convention in Pittsburgh.
He pulled a folded target from his suit pocket to show me a tiny, one-hole, five-round, 100-meter group he had personally shot with the new Eley load through a prototype Anschutz 17M2 rifle. His view was that it was the most accurate rimfire ammunition he had ever fired, and Dieter Anschutz knows something about rimfire accuracy. And consider that Remington has contracted Eley to produce Remington-label .17M2 ammunition to the same specifications and has also added an Eley-made/Remington-label .22 LR competition/target line of ammo to its catalog.
So how does Eley do it?
How Eley Does It
Last November Eley and its exclusive U.S. distributor, Zanders Sporting Goods, offered a group of Primedia writers and editors the opportunity to visit the company's just-opened manufacturing facility in England, allowing outsiders, for the first time in Eley's history, to observe its manufacturing techniques. It was an amazing visit. I can't tell you everything we saw because of proprietary considerations, but I can tell you that I will never think quite the same way about how ammunition is engineered and produced.
The company was founded in London by brothers William and Charles Eley in the 1820s and has been in business ever since--albeit under a variety of corporate identities and ownerships. Major ammunition developments that have come from Eley include a joint patent with Samuel Colt for Colt revolver cartridges, in 1855; Britain's first centerfire cartridge, produced in 1857; fundamental patents during the 1860s in the development of the Boxer primer system; development of the first bottleneck rifle cartridges, in 1869; and thin-brass totally waterproof shotshell cartridges, in 1882.
During the American Civil War, Eley was a major supplier of ammunition to the Confederacy. Its first .22 rimfire cartridges were produced in 1860, but the move toward Eley's present world rimfire prominence really didn't begin until 1951 with the introduction of the first generation of TenEx.
Eley's goal behind the initial TenEx development was to provide British-made .22 LR ammunition, built to extreme consistency, that British shooters could use to win British shooting competitions. (American-made Western Supermatch and Winchester EZXS were the dominant competition loads of the time.) It worked. The 1951 British Championship and the Grand Aggregate events at Bisley were won by Eley team shooters using TenEx.
It was the first time these titles were won using British-made ammunition. Eley spent the following decade readying TenEx to compete in the international market, steadily improving the quality by means of a "half tolerance" standard for TenEx components compared to standard ammunition and the creation in 1962 of a segregated TenEx component manufacturing and cartridge assembly facility where half tolerance became the standard tolerance. Those wins at the 1964 Olympics and in the following years were the proof of their success.
Eley TenEx bullets are drawn from coils of proprietary alloy lead "wire" and, after passing visual inspection, are subject to computerized scanning for defects, with even the slightest imperfection cause for elimination.
Then came the breakthrough Eley executives view as the most important single factor in the TenEx story: Eleyprime. During the years that the engineers worked on perfecting Eley ammunition, they were also engaged in ongoing research into priming technology. Commonly used priming material is percussive; bump it, it goes bang; give it a spark, it goes bang; look at it cross-eyed, it goes bang. In the 1960s and 1970s ammunition manufacturers worldwide used essentially the same technology.
Concerned by the inevitability of explosive accidents no matter the precautions taken, Eley in 1975 embarked on a project to find a new priming process. In 1979 chemists working on a dry powder mixture for filling .22 cases discovered that it was non-explosive until exposed to water, whereupon a chemical reaction converted it to conventional lead styphnate (primer compound).
A closely guarded (and patented) secret, this new Eleyprime process had two huge consequences: It eliminated the risk of explosion from the preparation and dispensing of priming compounds, and it allowed the amount of priming material applied to each individual rimfire case to be very tightly controlled in a normal workshop environment using automatic equipment.
This last part is critical because it has long been known that case-to-case variation in the amount of priming material is the most important factor regarding variations in .22 LR rimfire performance. This is due to the fact that in small rimfire cartridges the primer is a significant portion of the actual propelling charge (much more so than in larger centerfire cartridges) and because conventional priming compound is too sensitive to be aggressively metered and applied.
The Eleyprime System allows exactly identical amounts of the inert powder to be put in each case. Then a round-tip rod is inserted down into the case to press the powder evenly into, and around, the rim, and a single, metered drop of water is added, which activates the compound over a several-hour period.
After drying, the cases can then be conventionally charged with precisely metered propellant (five rounds at a time on the TenEx loaders). Before Eleyprime, there was an average 31 to 39 milligram spread in the amount of priming material round-to-round in TenEx ammunition. With the Eleyprime System (EPS), the spread was reduced to only plus/minus 1.0 milligram. It was a stunning achievement, and in 1988 Eley received the prestigious Queen's Award for Technological Achievement.
Keeping The Lead
But technology does not stand still. TenEx maintained its preeminent place among premium .22 LR ammunition during the 1980s and 1990s, but other ammunitionmakers advanced their own manufacturing techniques. Eley monitored their rivals' progress, and in its own lab and testing ranges regularly compared the competitors' performance against TenEx.
Eley rimfire cases are formed from specially alloyed sheets of copper by progressive individual stamping under extremely controlled conditions. Each Eley TenEx case is individually subject to close visual inspection.
The performance standard Eley applied was 10-shot test groups, fired from a fixtured rifle (not a special test barrel) at 50 meters. The specification called for a nominal percentage of test groups to measure less than 15 millimeters (the diameter of the 10-ring on a standard 50-meter smallbore rifle target). As of 1998, TenEx performance ran 8 to 10 percent; that is, 8 to 10 percent of all 10-shot groups fired were less than 15mm diameter. It was the best in the world, but new loads from Lapua and Federal Cartridge's new match ammunition were knocking on the door.
Eley tasked its engineers to take a blank sheet of paper, start with the Eleyprime system as the only foundation, and reinvent the TenEx cartridge from the ground up. The goal was to improve TenEx performance to at least a 30-percent 15mm-group standard; in other words, make it three times better.
I'm not allowed to tell you how they did everything they did, but even in summary it's one of the most impressive achievements I've seen in my 30 years in this business. Eley engineers identified 50 primary variables--basics like bullet mass, case internal volume, and propellant charge mass.
Then they determined 200 secondary variables--things like the ambient humidity in the assembly facility, the metallurgy of the cases, human competence. Finally, they identified 700 tertiary variables--subtle things the TenEx project manager told me turned out to be the ultimate keys to getting things really up to "the TenEx level." For example: weather conditions in the country where the propellant powder is manufactured on the day that particular lot of powder was mixed. (Yes, Eley actually adjusts the TenEx loading profile for each powder lot based on this and other equally subtle considerations. The same is true of the other end of the process; manufacturing "lots" of TenEx consist of one day's run from a single loading machine because the weather is different each day.)
With nearly 1000 variables charted, the engineers addressed bullet and case design. Bullet design was analyzed with sophisticated computer modelling for in-flight characteristics. They discovered that a flatnose projectile was distinctly better for subsonic velocities out to 50 meters. The reason is that bullet stability is enhanced the more forward the center of pressure (air-pressure resistance) is located forward of the center of gravity of the bullet, and roundnose bullets do not "push" the center of pressure as far forward. (Incidentally, the small "pip" visible in the center of current TenEx bullets is not a ballistic feature; it's the result of an air pocket in the mold that allows the sharp-cornered edges of the nose to form fully.)
They also determined that the presence of lead oxide in a bullet was a primary cause of "detached shots" (what non-engineers call "flyers") because of differential resistance to passage through the bore. So TenEx bullet material is fabricated in an oxygen-free atmosphere and lubed with a soft tallow/beeswax material, the same lube Eley used 150 years ago; most modern bullet lubes are paraffin-based, which is harder.
I was particularly intrigued by the information that the engineers had determined the base of a bullet was much more significant for accuracy than the nose of the bullet. In-flight tests showed that a very slight mar, burr, or scratch on the bullet heel would almost always result in significant yaw angle upon departure from the muzzle. They could actually pinch the nose of the bullet with a pair of pliers and it would have a much lesser effect on point of impact. Consequently, the heel of every TenEx bullet is visually inspected by computer before loading, and bullets with even the slightest imperfection are discarded.
While visiting Eley's facilities, Dick had the opportunity to review .22 LR and .17M2 performance at England's famed Bisley range with Sako's new Quad rifle. The rifle and ammo were extremely accurate.
Cases are as carefully gauged as the bullets and are formed by a progressive stamping process that minimizes distortion or metallurgical impact. The overall length is carefully specced, the case mouths are perfectly flat cut (not sheared), and the composition of the brass alloy is tested for every lot.
The actual loading process is completely computer-controlled and monitored with hands-on visual quality control and sampling (200 rounds fired for performance standard from each lot) as a supplement. A key element of final testing is the uniformity of pull-out force (bullet from case), which is critical to overall consistency in point of impact. Incidentally, the only observable difference between the loading process for the Eley .22 LR TenEx and the new Eley .17 Mach2 ammunition is that the use of Hornady V-Max bullets in the .17M2 obviates all the special care taken with TenEx bullets.
Worth The Effort
Remember, the goal of the TenEx improvement project was to increase the percentage of reference groups (less than 15mm diameter at 50 meters) from 8 to 10 percent to 30 percent. Current Eley TenEx Ultimate EPS ammo averages 50 percent.
I had the opportunity to shoot both the new-generation TenEx and the new .17M2 ammunition through a variety of rifles--from match-grade Anschutzs to hunting-grade Rugers, including the unique new multicaliber Sako Quad (see sidebar). There's not much to report. As you can see from the targets, both loads will essentially shoot one hole from a premium-grade rifle at 50 meters. Would Olympic-quality Eley TenEx .22 ammo be of any worth to you? Everybody knows different kinds of ammunition shoot differently in different guns, and I would never claim that TenEx shoots one-hole groups in every gun you might try it in.
But I will say that in every gun I have ever fired TenEx in--pistol, revolver, or rifle--it has shot better groups in those guns than any other brand or type of ammo. I think it's a great small-game hunting load (50-yard squirrel head shots from my scoped S&W Model 41 .22 autoloader). And you don't have to be an Olympian to benefit from Eley quality.