This kit reduces recoil and increases longevity of the spring system in Springfield 4" guns.

If you have a .45 ACP or .40 S&W you will need the kit with the 22lb flat wire spring available here.

The kit includes a 1/4" guide rod, reverse plug and ISMI flat recoil spring.

All systems use a 1/4" guide rod made from solid barstock with a take down hole.

Reverse plugs are Blued carbon steel.

Meant for use in Springfield 4'' 9mm 1911's only.

All kits are drop-in.

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.