The World’s NO.1 square spring. The perfect replacement or upgrade for standard mainsprings. 

Warning – replacing your air rifles mainspring may increase its power making it illegal. Redbeck Shooting Supplies would recommend that you seek manufacturers advice or a professional gunsmith before attempting to alter your rifle, and that you always check your rifles power using an accurate chronograph to ensure you stay within the law.NO1 FITS – BSA Airsporter, Lightning, Anschutz 335, Original 35, 38, 45, 50, RWS 24, 27, 34, 45, 50 reium, HW50, HW55, HW57, HW85, HW90, HW99, Haenel Lion, ASI CF 16/20, Webley Mk3 (if the spring guide is reduced by 20 thou) NO2 FITS – BSA Meteor, HW57, Milbro Diana G80 and 27, Norica, Baikal NO3 FITS – BSA Superstar (12ftlbs only), Webley (all models) NO4 FITS – HW35 (Diana Orig RWS 52, 48) NO5 FITS – HW80, Webley Eclipse NO6 FITS – HW77, HW(&, Feinwerkbau Sport, Also larger original models if ultimate power required NO7 FITS – ASI Sniper, Magnum (and all other ASI models) Diana 79 and Gamo