Discover the GMI Engineering Lineup

At GMI Engineering, we pride ourselves on delivering precision-engineered solutions for airgun enthusiasts, competitive shooters, and small-scale manufacturers. Our range is designed with accuracy, reliability, and value for money at its core — and we now offer complimentary worldwide shipping.

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• Our SOC – Single Cavity Swaging Kit is the perfect entry point for beginners looking to craft high-quality slugs. Starting from just $350, the SOC comes with multiple punch and nose options, allowing you to produce almost-solid nose and hollow point slugs. Compatible with calibers from .177 all the way up to .457, this kit ensures you can explore the full spectrum of airgun ammunition customization —

  • ​​Explore SOC →

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• The Slug Master takes performance to the next level with an auto-bleed system, adjustable hollow-point depth, and a boat-tail punch alongside standard punches. It now also includes adjustable grain (weight) settings—fine-tune slug weight with interchangeable metering/bleed adjustments to match velocity and barrel preference. Designed for calibers from .177 to .30, this professional-grade swaging kit is currently on sale from $500 —

  • Explore Slug Master →

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• The Pellet Master is a compact, single-cavity mold system designed for effortless pellet making. Unlike traditional molds, it requires no bolt tightening, loosening, or heavy bars — just simple, smooth operation in a space-saving form factor. Perfect for both hobbyists and small-scale production, the Pellet Master will tentatively start from $600 —

  • Explore PelletMaster →

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• The Freedom Press is GMI Engineering’s flagship swaging press, built for extreme precision, smooth operation, and long service life. Constructed from premium-grade materials with a rigid frame and low-friction operation, it’s designed to work seamlessly with our Freedom Series Dies. Ideal for both hobbyists and professional slug makers, the Freedom Press delivers consistency shot after shot —

  • Explore Freedom Series Press →

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• Our Freedom Series Die Set is precision-machined for compatibility with the GMI Engineering Freedom Press and, with a suitable adapter, the Corbin S-Press. Offered in calibers from .177 to .457, the set now features adjustable grain (weight) options so you can dial in preferred slug mass across profiles. Includes solid nose and boat-tail options for ultimate flexibility —

  • Explore Freedom Series Dies →

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• For Preslug press owners, the Preslug Aftermarket Die Set delivers a plug-and-play upgrade. Available for calibers from .177 to .30, this set now supports solid slugs with boat-tail profiles, offering better aerodynamics and downrange stability —

  • Explore Preslug Dies →

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• The Corbin Press Adapter is engineered specifically for the Corbin S-Press, enabling customers to install and use Freedom Series Die Sets without modification. Machined from high-strength materials for perfect alignment and rigidity, this adapter ensures seamless integration, letting Corbin users experience the precision and versatility of the Freedom Series —

  • Explore Corbin Adapter →

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At GMI Engineering, every product is backed by our dedication to quality and our mission to deliver tools that help you push the limits of precision shooting. Whether you’re starting out or optimizing your production setup, our portfolio has the perfect solution for you.