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No. 1 With a Bullet


Hornady Manufacturing Co. – the largest independent bullet maker in the United States – purchases lead billets and rolls of copper by the truck-load to make its popular copper-jacketed bullets. Throughout the companys time-honed manufacturing process, Hornady relies heavily on effective lubrication as it combines these two metals into the most consistent, perfectly formed and accurate products possible.

The lead billets are molten, cast into cylinders, and extruded into lead wire – which becomes the lead core of copper-jacketed bullets. As part of the bullet forming process, the lead is lubricated with a total loss lubricant: Hornady applies a light quench oil to protect the forming dies, and to prevent the lead from sticking to the die. When each core is formed, a small scrap of lead is lost. In accordance with Hornadys strict recycling policy, this scrap is collected and added to the companys lead smelting pots. When the scrap is added to the pot (which is kept above 750 degrees F), any quench oil remaining on the scrap collects on top of the molten lead, where it burns off – creating numerous issues for the company.

Production Supervisor Mike Timmerman set out to resolve the situation. We tried different ductwork, installed a baffle system, changed to a larger fan motor, and even installed a $15,000 cyclone, he recited. Nothing worked. Finally, we tried changing the oil.

After investigating the options, Timmerman tried a soybean based quench oil with a flash point of 600 F, in place of the previous petroleum oil (which had a flash point below 400 F). Before switching, Hornady workers had to baby the scrap back into the pot, or it would flare up. According to Timmerman, with the soy based lubricant there is now 50 percent less smoke, zero flare-up when recycling the scrap lead, and very little smoke and no fire makes this a much better process. How do you put a dollar figure on safety?

In 2003-2004, the U.S. Environmental Protection Agency awarded research funding to the University of Northern Iowas Agriculture-Based Industrial Lubricants (ABIL), under a regional initiative entitled, Pollution Prevention Incentives for States. The grant provided for ABIL to conduct a series of cooperative field feasibility studies, observing soybean based metalworking fluids already at work in metalworking shops in Iowa and Nebraska.

ABIL has been active in the research and development of environmentally friendly, soy based industrial lubricants for more than a decade. Since 2001, laboratory studies have revealed inherent benefits for soy based metalworking fluids, such as increased lubricity for better tool life and improved work piece finishes, improved adhesion to metal surfaces and thin-film strength, and higher flash and fire points. Under controlled laboratory conditions, soy-bean oil based MWFs performed admirably – but more research was desired to prove their performance in real-world industrial applications and working machine shops. The goal of this project would be to expand on existing research results by asking metalworking shops using soy fluids to share their insights and experiences, and develop case studies to be distributed on the ABIL web site ( At the conclusion of the study, almost all shops participating had decided to continue or expand their use of soy based MWFs.

In Hornadys case, Timmerman began testing soy based MWFs in February 2004. By August, when the company was invited to participate in this project, several applications in the facility were using lubricants developed by ABIL researchers, and manufactured by Environmental Lubricants Manufacturing under license through the Universitys Research Foundation. After completing data-collection worksheets developed by the Universitys Institute for Decision Making, a partner in the study, Timmerman agreed to provide project staff with a process tour at Hornadys Nebraska facility to observe firsthand the improvements experienced after switching to soy.

A thin ribbon of copper is fed into cupping machines which stamp circles from the metal, like a cookie cutter through cookie dough. Lubrication is applied to both sides of the copper as it feeds into the machine – about one drop every five seconds. (Extra oil doesnt improve the process and the lubricant is lost in use.) Leftover copper comes out looking like Swiss cheese; the flat copper circles are formed into cups, waiting to become bullet jackets.

These copper cups, along with lead bullet cores, are fed into the bullet press, where the two are swaged together and formed by a series of dies until the completed bullet exits the machine. Once the copper-jacketed bullets have been produced, residual forming fluid is cleaned from them, leaving a shiny copper finish.

Using petroleum oil, jacketed bullets had to go through a bullet washing machine, which used water and abrasive cleaning agents to remove the lubricant from the bullets. The bullet washing equipment was beginning to show signs of its age – requiring more frequent maintenance – and Timmerman was considering the purchase of a new machine. After washing, the copper-jacketed bullets required more finishing, passing through a cement mixer-like tumbler with polishing media to remove the most stubborn oil residue. Finally, the mixture would run through a series of screens to separate the finished bullets from the polishing media.

When Timmerman initially tested soy based lubricant in the copper process, not everyone was convinced it would work. Obviously, change is hard, so my folks were skeptical to say the least, he recounted. Now that we have some time behind us, those concerns are gone and the product has been well accepted.

Hornady found the performance of the biobased oil to be equal to the previous product and it uses about the same amount of new oil as before. Though the company didnt have to alter its machines or process to support the biobased oil, the cost of oil increased from $8 per gallon for the old product to $14.45 per gallon for the soy based product; for Hornady, this adds up to roughly $350 per month. The benefits gained from using the new soy based oil, however, more than outweigh the cost, considering the impressive savings Timmerman was able to achieve in Hornadys bullet cleaning process.

The companys previous petroleum based lubricant was heavier and harder to clean off the bullets, requiring a stronger, abrasive cleaning agent to wash oil residue from the finished copper-jacketed bullets. Because the soy based oil cleans up more easily, Timmerman switched the process to a gentler liquid soap just to break down the oil; we dont need the abrasive anymore. The usage rate for soap has dropped by two-thirds, and theres no abrasive sediment to shovel out of Hornadys all-inclusive onsite water treatment system.

Since switching to the soy based fluid, Timmerman has been able to completely eliminate the washing step from the process about 50 percent of the time, reducing the amount of water used and treated by over 7,500 gallons per month. At 8 minutes per load, reducing bullet washing also shortened the manufacturing cycle.

Reducing Hornadys reliance on its bullet washing machine also allowed the company to delay purchasing a new one; with less load on this equipment, Timmerman expects to continue using the current machine for the foreseeable future. This new lube has many implications for us. Weve started looking at different ways of processing finished product; it could save us from ever having to buy a new washer that would cost $300,000, Timmerman predicted. We could be looking, in the future, at not having to process wash water – the goal is to get away from washing with water at all, and to have a dry process.

Instead of needing a polishing media in the tumbler – The soy oil cleans up so much easier, Timmerman remarked – Hornady now sends the bullets through the tumbler with a couple of clean, red shop rags. Using rags instead of the media saves the staff from having to use shaker pans (screens) to separate the media from the bullets – which is OK with employees, since this was heavy, difficult work.

Finally, and most important, the change to soy based lubricants allowed Hornady to more easily achieve its high standards for quality, as measured by accuracy. After a few minutes of tumbling, the shop rags remove essentially all of the residual soy based lubricant, leaving a uniform, smooth, shiny finish on each of the jacketed bullets. This shiny finish is an important measure of quality for Hornady. Appearance is one of the measurements we use; we basically look for the best shine, and how the bullets hold their shine over time, Timmerman said. Less washing, less tumbling, and less handling improves the accuracy of these bullets. Less handling equals fewer scratches in the surface, a more regular finish, and better accuracy.

Using this product, the finish is better than it ever was, even after washing the bullets – the customers are happy (theyve noticed the difference), theres no media in with the bullets, and there is a better polish.

Having completed the field observation and data collection stages in 2004, ABIL scientists began to incorporate lessons from this project into its ongoing development of soy MWFs. Tapping into the real-world experiences of the studys seven industrial partners, combined with rigorous laboratory research conducted at ABIL, has provided significant performance advances for both soy based neat oil and soy based coolant formulations – leading to more versatile fluids with superior performance and increased longevity in traditional machining operations.

Current ABIL research focuses on developing soy based formulations to complement the progressive fluid management practices being adopted in the metalworking industry. As machining operations become more demanding and materials become more exotic, and as metalworking fluids and fluid management techniques gain visibility on the bottom line, biobased products will be well positioned to capitalize on these changes.

Asked for his perspective, Timmerman noted that the benefits of soy based oil out-weigh the cost. Its environmentally friendly, it works as well as the petroleum-based oil, its 10 times easier to clean off, it allows for less tumbling and washing, and it generates less waste. He has no regrets about his decision, calling it, spot on. Its been that way since the day we put it in, right up until this moment – weve not had one problem with the lube since. Timmerman reflected, You dont often get to hit a home run – usually the improvements we make are singles and doubles. I knew this one was a home run, out of the park, in the first week we used this product.

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