The Ismi 17 lb. C/S Spring is a precision 1911 mainspring designed to optimize trigger feel and hammer dynamics for Government and Commander model handguns. Built to deliver consistent cycling and reliable ignition, this main spring enhances action performance across a range of 1911 pistols, making it an ideal upgrade for enthusiasts and professionals seeking a crisp, reliable pull without sacrificing durability. Crafted to fit the 1911 and Commander configurations, it integrates smoothly with standard components to maintain proper timing and hammer strike, while the 17-pound weight provides a balanced balance between responsiveness and control. Whether youre adjusting the mainspring for competition accuracy, duty readiness, or personal defense, this replacement part supports smooth cocking, dependable ignition, and consistent lockup in long-term service. Ismis attention to material quality and precise fabrication ensures compatibility with compatible 1911 platforms, delivering predictable performance under varied conditions. Use this mainspring as part of a thoughtful tune-up to optimize your handguns action, reduce fatigue during extended shooting sessions, and preserve reliable cycling when it matters most, all while maintaining a clean, professional profile in your firearm maintenance workflow.