Theoben Rapid Forum

Gents,
Just had the need to strip and rebuild my Impact GSX200 as it had sprung a leak. The rifle is .20 calibre and has a 350mm barrel. Although I bought it secondhand as far as I am aware the original owner hadn't tampered with it.
Prior to the leak it was running at 11.3ftlbs with 13.5gr pellets. Before rebuilding the regulator I put it in the tester and to my surprise the set point was just above 70bar/1000psi. Another strange one was the hammer spring set up which had two springs, what looks like a shortened standard Rapid spring and a smaller spring inside the other. The spring guide was also stepped to accommodate both spring sizes. The rifle had been reasonably accurate with the odd flyer but always had quite a wide shot spread in the region of 25 - 30fps over a full magazine
I am led to believe the regulator set point for a .20 calibre should be in the region of 100bar/1450psi to achieve the best results. With the spring tension at maximum I have tried changing regulator set points with the following results, 80bar/10.0ftlb, 90bar/9.5ftlb, 100bar/9.0ftlb. Your thoughts would be greatly appreciated

Hammer Springs_1.jpg
Hammer Springs_2.jpg