EGW Mainspring (Hammer) ISMI 17 lb

Available in 17lb or 19lb. All ISMI Springs are made from silicone chrome instead of 150 year old music wire.

Every ISMI spring is heat treated, shot peened & stress relieved to enhance durability, consistency and reliability.

ISMI is a contractor of the U.S. government and produces springs used in machine guns with incredibly high cycling rates. Also, the creator of ISMI springs obtained his knowledge from extensive research in the development of springs used in Indy car racing.

In independent testing, ISMI spring have endured in excess of 100,000 compression cycles. We don’t recommend going that long between changes however. With an ISMI spring, practice routine maintenance and change it once a year.

By purchasing EGW Mainspring (Hammer) ISMI 17 lb from our online store, you are guaranteed to receive a high-quality item. We work with trusted brands to offer shooting and hunting enthusiasts, both amateur and professional, quality products at a reasonable price. Choosing to buy from us means opting for quality and practicality