We proudly use ISMI springs in all of our builds and component assemblies.  Over the years, we have spent a lot of time switching back and forth between spring manufacturers for our builds before finally making the decision to stick with ISMI.  The longevity and consistency of their springs has proven to be unmatched.
 
These springs are designed for use with Gen 1-3 pistol with a captured or uncaptured guide rod.  Units for Gen 4-5 pistols will include an ISMI Guide Rod Adaptor.
 
Manufactured from Chrome Silicon alloy. Flatwire recoil springs available in a variety of weights to allow for exact tuning of sight movement, overall feel, and load tolerance. Designed for maximum longevity and performance.
 
ISMI rods are machined from stainless steel and utilize a button head screw to retain the spring when the assembly is out of the pistol. This allows the shooter to dis-assemble the guide rod for spring replacement or maintenance.