Originally Posted by pmflexxx
Any performance hit on the bolt upgrade to make it backwards compatible with earlier Geos esp those without the solenoid adjuster? Are the GSL/3.5 internals better tuned for the IV core?
The IVCore Kit will bring a Geo3/3.1 up to the same level as a GSL and Geo3.5
The IVCore kit will bump up the efficiency of a Geo, Geo+, SL91, Geo2 and Geo2.1 but don't expect them to be as efficient as a GSL/3.5 The solenoid design of the pre-Geo3 guns will always see them produce slightly worse efficiency figures than a post-Geo3 gun. The newer ISCIS system is just a more robust, reliable and more efficient design.