ISMI – 17 Pound Hammer / Main Spring

ISMI – 17 Pound Hammer / Main Spring

ISMI Springs are designed for maximum consistency and reliability.  American made and CAD designed and built to aerospace specifications from Chrome Silicon wire for maximum durability, consistency and reliable performance.  Heat treated, shot peened and fully stress relieved to minimize spring set.

Chrome Silicon (CS); wound in the very popular 15 lb, 17 lb, 19 lb. and 22 lb. rate. For lighter, consistent trigger pull over the factory 23 pound mainspring while still providing reliable ignition.

12 Month Replacement Warranty

All ISMI springs are covered by a 12 month replacement warranty. Even for failure due to wear.