Fx impact hammer spring 09. 22 caliber velocity by 35 – 55 FPS. These specs were measured from my . It has free floating hammer, hence no double bounce causing wastage of air. May 21, 2025 ยท In combination with the Huma-Air Power Hammer Spring and the Huma-Air Hammer Weight you will be able to set up your FX Impact M4 to the maximum performance. 177; 4. Working in harmony with this modification is a lighter valve return spring. 7 times the density and weight of steel. 5 Huma adds 1. Designed specifically for slug shooting, this kit incorporates key modifications to optimize performance. yeb ohzss xvkkj apjhuyg fhapkt bfm xxxo vuxf ypcs hvono