Hammer Main spring (heavy wire)
Thicker wire for guns shooting high velocity and over .22 cal, if you are shooting mid range power then this will make the rifle over sprung and not efficient, choose standard wire spring.
All Hammer springs need cutting to length, keep trimming a coil at a time until you see a slight power reduction over a chronograph, then you are not overworking the rifle.
Fits all Rapid Air Weapons/Worx Airguns.
Fits all Theoben Rapid Airgun models.
