Coonan 357 Magnum full-size grips

Coonan 357 Magnum full-size grips

Coonan .357 Magnum full-size was the groundbreaking flagship pistol that defined Coonan Arms. In 1977, while studying industrial design, Dan Coonan set out to create a 1911-style semi-automatic that could safely and reliably fire the powerful .357 Magnum revolver cartridge—an ambitious project considered nearly impossible due to rimmed case feeding challenges and extreme pressures

After extensive prototyping and solving double-stack magazine geometry, the first functional Coonan .357 Magnum Automatic was completed in 1981. Production began in 1983 in St. Paul, Minnesota, making it the world’s first commercially successful .357 Magnum semi-auto pistol

The full-size model featured a 5-inch stainless steel barrel, M1911-inspired controls, 8+1 capacity (double-stack magazine), all-stainless construction, recoil buffer system, and robust frame/slide to handle magnum loads. It delivered revolver-level stopping power with semi-auto speed, appealing to law enforcement, hunters, and enthusiasts

Though expensive and produced in limited numbers, the Coonan .357 earned a cult following for its bold engineering. The design laid the foundation for later Coonan models and proved large-rimmed cartridges could work reliably in 1911-pattern pistols. Production continued under various ownership until the company’s closure in 2019

The grips are compatible with various modifications of full-size model:

  • Coonan 357 Magnum Classic
  • Coonan 357 Magnum full-size
  • Coonan Model B
  • Coonan Model C