Repair/Replacement Spring Kit for the FN Five-seveN barrel.
:The 8 pound spring is used to resolve FTE issues when adding weight to your slide like a red dot or muzzle device. All EFK 5.7 threaded barrels are now assembled with the 8 pound spring.
:Use the 10 pound spring if you feel that you are getting to much recoil and the slide is coming back to hard.
When running suppressed it it best to use the lighter spring to compensate for the added weight of the suppressor. Also running the lighter spring allows you to run subsonic ammo.
With the 5.7x28 being a very finicky round reliability comes down to how clean and oiled your firearm is, along with your proficiency in firearm handling.
