ISMI Recoil Springs for 1911

ISMI’s proprietary design features enhance the spring’s ability to hold the pistol in battery longer when fired to maximize energy dispersion and reduce sight movement. 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.

A note from the manufacturer: Maximum Service Temperature of ISMI’s material goes up to 700°F. Music wire has a maximum service temperature of 250°F and can be negatively affected at temperatures as low as 175°F. This is important because temperatures approaching, or exceeding, the maximum service temperature are highly detrimental to spring life. Exposure to maximum service temperatures promotes additional spring set and is detrimental to the relaxation of the spring. In other words, the spring will not decompress as rapidly as it should.

Available in 7, 8, 9, 10, 11, 12 ½ , 14, 16, 18, 20lbs.