ISMI premium recoil springs manufactured exclusively with certified aerospace specification alloys; stainless or chrome silicon. The springs are heat treated, shot peened and stress relieved after winding to enhance performance and durability.
FLAT WIRE SPRINGS
Manufactured from Chrome Silicon alloy to maximize spring longevity and load. These springs offer the ability to replace worn out factory parts, tune sight movement, or tune the pistol for a specific load. The benefits of switching from conventional round wire to flat wire include improved cycling, spring longevity (upwards of 50k compression cycles), and more tolerant to a wider variety of loads.
Advantages of flat wire recoil springs:
- more effective cushion as opposed to round wire; allow more rapid compression/decompression than round wire springs; tolerate high impact loads better
- ability to operate flawlessly with anything from lighter match loads to +P duty ammunition; flat wire springs have more energy than round wire springs and are more efficient
- Larger surface area distributes impact more evenly reducing wear and tear; flat wire springs have a longer life than round wire varieties = less frequent replacements and smoother recoil
- ejection is more consistent and smoother
- Flat wire springs more resistant to friction, buckling, and breakage, with a lower failure rate
The flat recoil spring must be used with a guide rod of ~.250” diameter, due to the smaller inner diameter of the spring.
General use guidelines for Govt. size pistols using FLAT wire springs. Will vary pistol to pistol:
- 24lb – 10mm/460 Rowland loads
- 22lb – for use for .45 ACP from target to +P loads
- 18lb or 20lb – standard duty/carry .45 ACP
- 18lb – 40 S&W standard duty/carry
- 15/16lb – 38 Super & .40 S&W competition
- 13lb – 9mm standard duty/carry
- 11lb – 9mm major Open (may have to remove some coils)
ROUND WIRE SPRINGS
Manufactured from Chrome Silicon alloy to maximize spring longevity and load. These springs offer the ability to replace worn out factory parts, tune sight movement, or tune the pistol for a specific load.
Guidelines for ROUND Wire Recoil Springs, Govt length:
- Nominal rating for .38 Super & 9mm is 14 Lbs.
- Factory rating in .40 S&W is 19 Lbs.
- Factory Standard for 45ACP: 16 Lbs.