Titan XS Mainsprings. For over 30 years Titan Mainsprings have been supplied worldwide to airgun enthusiasts, professional airgun customisers and the Gun Trade. Only the finest quality Grade 1 Swedish Silicone Chrome Vanadium Spring Steel is used. We use no mass production methods, each spring is hand wound to an exact specification, then heat treated and tempered to ensure ultimate performance and maximum durability. During final tempering, they are coated with a specially formulated hard, but flexible finish. The almost friction-free operation of the Titan XS mainspring reduces the possibilities of dieseling to a minimum and increases power by up to 40% for FAC rated air rifles. Fitting this spring may take the rifle over the legal limit. Sizes available are: No.1 BSA Airsporter, Mercury, Challenger, 635 Magnum, Supersport, Lightning, Xl, XLSE, Superstar, Goldstar, Centenary. Air Arms Firepower, Jackal, Woodsman. Original Mod. 34/35/36/38/45/(48/52std power), 54, RWS Firebird, Falke Mod 80-90, HW77(std power), HW99, FWB 124/127. No.15 HW45, HW25, Orig Mod 20. For all other models please get in touch.