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