ISMI Chrome Silicon Gun Springs
ISMI springs are the reference standard competition shooters reach for when factory springs aren't good enough. Every ISMI spring is manufactured from chrome silicon alloy — not the 150-year-old music wire still used in most factory and lesser aftermarket springs — then heat treated, shot peened, and stress relieved to maximize service life and maintain consistent spring rate under the sustained cycling of competition use. When CSRG, Grams Engineering, and other follower/spring kit manufacturers need a spring they can trust, ISMI is frequently the spring inside.
Shop ISMI Springs by Platform
- 1911 / 2011 — firing pin springs (standard and extra power), recoil springs, mag catch springs
- Glock — striker springs in multiple weights for trigger tuning
- Sig P320 — trigger return springs, sear springs (OEM, -10%, -25%, -50%), reduced striker safety springs, magazine springs for 17 and 21-round tubes
- Sig P365 / P365XL / Macro — reduced power striker springs, striker block springs, sear springs, recoil springs, captured guide rods
- CZ P-10 / CZ 75 / Shadow 2 — flat wire chrome silicon recoil springs
- Canik TP-9 / Rival / Mete — trigger return springs, striker springs, safety block springs
- Beretta 92 / M9 — hammer springs, trigger return springs, firing pin springs
- S&W M&P — flat wire chrome silicon recoil springs
- Springfield XDm — chrome silicon recoil springs in 14, 16, and 18 lb ratings
- AR-15 — extra power 30-round magazine springs
Why Chrome Silicon
Standard music wire springs lose tension faster under repeated compression — the exact stress competition shooters put on recoil, striker, and magazine springs at high round counts. Chrome silicon alloy resists that fatigue significantly better, and ISMI's heat-treating and shot-peening process further improves fatigue resistance and consistency. The result: a spring that holds its rated weight longer, which means more consistent trigger feel and more reliable cycling deeper into a high-volume practice season or a multi-day match.
Many of our follower and spring kits — including CSRG and Grams Engineering competition kits — are built around ISMI springs. If you're replacing a factory spring on any of the platforms above, ISMI is a reliable upgrade on its own.