Day & Zimmermann Announces Renaming of South Dakota, Yankton Facility

Empire Products, Inc (EPI) officially adopts the Day & Zimmermann name and brand as Acquisition Integration Reaches Completion

Yankton, South Dakota – January 6, 2026 – Day & Zimmermann (D&Z), a leading provider of defense solutions, munitions production and life‑cycle support for the U.S. Army announced today that its Yankton facility—formerly known as Empire Products, Inc (EPI)—will officially adopt the Day & Zimmermann name and brand.

Day & Zimmermann’s Yankton facility proudly serves America’s warfighters. Building on D&Z’s long munitions manufacturing legacy, the facility produces 155 mm and 120 mm propellant bags for the U.S. military. Driven by rising demand, the operation has grown rapidly—from just eight employees to nearly 60 in just over two years—and continues to expand. The company remains committed to recruiting top talent and providing long-term career opportunities across all D&Z plants.

This milestone marks the completion of the facility’s integration into the Day & Zimmermann family of companies, strengthening alignment across D&Z’s national footprint and enhancing recognition among customers, partners, and the communities the company serves. Rooted in more than 125 years of history supporting America’s national security mission, D&Z continues to advance its legacy through the specialized work performed in Yankton.

“We are proud of our Yankton facility and the vital role our team plays in supporting the U.S. military. The Yankton team now shares our century-long identity as Day & Zimmermann,” said Brigadier General (Retired) John McGuiness, President of Day & Zimmermann Munitions & Government Group. “The Yankton team’s growth, capabilities, and dedication, strengthen our mission and illustrate the tremendous value this facility brings to our company and to America’s warfighters.”

Empire Products, Inc. (EPI)’s transition to the Day & Zimmermann name is a final step in the 2023 acquisition, and will not change the facility’s operations or commitments to customers, partners, or the local community. Employees will continue performing the same critical work that contributes to national defense readiness.

Day & Zimmermann Munitions- Strengthening the U.S. Defense Industrial Base

Since helping design and operate the Iowa Army Ammunition Plant (IAAAP) in 1941—and serving as its government‑owned, contractor‑operated (GOCO) partner continuously since 1998—D&Z has expanded to a five‑state network that now includes Parsons, Kansas; Texarkana, Texas; and Yankton, South Dakota, which are home to fully-owned D&Z munitions plants, along with Milan, Tennessee and Middletown, Iowa, where D&Z subsidiary American Ordnance operates these GOCO facilities. Together, these sites provide the Army with mortars, artillery projectiles, grenades, propellant systems, and a wide range of energetic components essential to modern warfare.

Day & Zimmermann delivers a full suite of energetic solutions, from Iowa’s American Ordnance artillery and Mine Clearing Line Charge (MICLIC) lines, to record‑setting M67 hand‑grenade and combustible cartridge case production in Texas, and precision propellant and charge bags manufactured in South Dakota. The company’s capabilities span mortars, 105 mm and 155 mm projectiles, smoke and area‑denial payloads, CAD/PAD devices, primers, warheads, tank ammunition, 40 mm cartridges, cratering charges, and other critical energetic components—all manufactured within the United States to strengthen the defense industrial base and support allied readiness.

About Day & Zimmermann

Founded in 1901, Day & Zimmermann is a family‑owned provider of construction, engineering, staffing, and defense solutions for government and commercial customers. Through its wholly owned affiliates American Ordnance LLC, Day & Zimmermann Kansas LLC, Day & Zimmermann Lone Star LLC, and Yankton Operations, the company operates multiple U.S. Army ammunition plants, delivering safe, high‑quality munitions that strengthen America’s defense industrial base and support allied readiness worldwide. Learn more at www.dayzim.com.

For more than a century, Day & Zimmermann has performed a vital role in the defense of our nation. With deep‑rooted experience, ongoing investments in modernization and automation, and a commitment to safety and quality, Day & Zimmermann remains focused on strengthening the domestic defense industrial base and supporting U.S. and allied readiness worldwide.